US President George W Bush has demanded that Israel withdraw its troops from Palestinian cities and implement a ceasefire.

At the same time, he said that Palestinian leader Yasser Arafat had consistently failed to combat terrorism, and urged Arab countries to help curb the violence.

Mr Bush also announced that he was sending his Secretary of State Colin Powell to the Middle East next week to seek broad international support for his proposals. 

Mr Blair is heading for the United States on Friday for a weekend summit with US President George Bush in Texas. 

Ahead of the meeting, the prime minister echoed the president's call for Israel and the Palestinians to act to halt the current conflict. 

Meanwhile, the United Nations Security Council in New York has unanimously passed a resolution calling on Israel to pull back "without delay". 

 

By Jonathan Amos  BBC News Online science staff

Scientists have laid bare the "life code" of rice. 

Two groups of researchers report a draft DNA sequence of the plant - a staple for more than half the world's population - in the journal Science.

The genetic information should speed up the breeding of tougher and higher-yielding varieties that can help feed the world's burgeoning population.

The journal has drawn fire for the deal it has struck with Syngenta

The genomic data will also prove invaluable in boosting the productivity of the other grasses on which humans depend, such as maize (corn) and wheat.

The research shows that a rice plant probably has more genes than a human - perhaps as many as 50-60,000 genes, compared with our 30-40,000.

But the rice genome, like the gene sets of all plants, contains tremendous duplication. Something like three-quarters of all rice genes are repeated in the code. 

Much duplication

Scientists think plants copy their genes and then modify them as a strategy for coping with the selective pressures associated with evolution. 

The Beijing Genomics Institute and the University of Washington Genome Center, with colleagues at 11 Chinese institutions, read the code of the rice strain known as indica, the predominant subspecies in China and other Asian-Pacific countries. 

The second team, fronted by the Swiss-based Syngenta company, decoded the japonica, or Nipponbare, subspecies, which is popular in more arid regions and, in particular, Japan. 

The genetic difference between the two is small but significant - about a half to one percent variation in the code. This is about 10 times the variation you would find in the genetic codes of two humans.

Rice, known scientifically as Oryza sativa, is the second plant to be decoded. The first was the tiny mustard plant, Arabidopsis thaliana, used as a laboratory model to investigate plant biology.

Rice, however, is the first food crop to be sequenced.

Another method

Both teams used the Whole-Genome Shotgun technique, the same method employed by the private company Celera to read the human "code of life".

And just like Celera, Syngenta has struck a deal with the Science journal editors that ensures it keeps proprietorial control over the japonica sequence.

Rice

Type of grass that grows from about 60 to 180 cm tall  Edible grain is the primary food for over half the world's population  World rice production totals nearly 600 million tonnes  China (including Taiwan) and India produce more than 50% of the total crop

The code has not been deposited in a public database, GenBank, as is customary, but in an escrow account held by Science and a separate system run by Syngenta.

Researchers wanting to work on the sequence will have to sign usage agreements with the Swiss company. Critics claim the access restrictions go against the spirit of open research and will slow the advance of new knowledge.

A consortium of public laboratories, known as the International Rice Genome Sequencing Project (IRGSP), financed by Japan, is also sequencing the Nipponbare subspecies. 

The consortium has opted to use a more systematic, traditional route to decryption which, though more precise, can take longer. The IRGSP is expected to publish its results later this year.

UK Prime Minister Tony Blair is heading for US President George Bush's Texas ranch for a meeting set to be dominated by the Middle East crisis.

Ahead of the weekend talks, the prime minister echoed Mr Bush's call for Israel and the Palestinians to act to halt the current conflict.

When the hatred is this bad you've just got to try and understand what is happening out there

Tony Blair UK prime minister

Plans for military action against Iraq over its alleged build-up of weapons of mass destruction had been expected to dominate the summit in Texas.

But the focus shifted to the Middle East conflict amid escalating violence and after President Bush called on Israel to withdraw from Palestinian areas and implement a ceasefire.

Arafat criticised

Mr Bush's unexpected decision to send Secretary of State Colin Powell to the region is being seen as evidence that he realises he must intervene there if he is to win international support for any future strike against Iraq.

Mr Bush: Both sides must act to halt conflict

The president has also criticised Palestinian leader Yasser Arafat for failing to stop suicide attacks by militants.

On Friday, in an interview for ITV's Tonight with Trevor McDonald, Mr Bush said it was a "silly notion" to suggest that the US had not done enough over the Middle East, saying: "We acted strong."

He said he was sending Mr Powell to the region "because I began to worry that the foundations that are necessary to a lasting peace were becoming eroded".

Mr Blair, speaking to the BBC World Service, said there was an "obligation" to do everything possible through political dialogue to end the violence.

He said: "We understand that we've got an obligation to do everything we possibly can to stop the terrible, dreadful violence that is happening in the Middle East at the moment.

'Catastrophe'

"It's for that reason that President Bush made his speech yesterday - he set out very clearly the basic principles that have to underpin any process, the recognition of the right of Israel to exist secure in its own borders, and a viable Palestinian state."

I made up my mind that Saddam needs to go. That's about all I'm willing to share with you

US President George Bush

The prime minister warned earlier on Friday that the situation in the Middle East has "the makings of a catastrophe".

In an interview with NBC News, Mr Blair drew parallels with the peace process in Northern Ireland, saying the violence would not stop unless a "proper political process" was put in place.

He said: "When the hatred is this bad you've just got to try and understand what is happening out there."

He said any breakthrough could only come if the Arab world "positively and explicitly" recognised the existence of the state of Israel, with Israel accepting that "a viable Palestinian state" must emerge from the peace process.

'All options'

Mr Blair and Mr Bush are also expected to address the possibility of military action against Iraq during their meeting.

Mr Bush said in his ITV interview that they would discuss "all options" but there were "no immediate plans" for action.

He said: "I made up my mind that Saddam needs to go. That's about all I'm willing to share with you."

Mr Blair is expected to land at Waco, Texas, at around midnight UK time before travelling to the president's ranch in Crawford.

Downing Street has stressed that the trip is taking place with the full agreement of Buckingham Palace and that its tone "will be in keeping with the period of national mourning" following the death of the Queen Mother.

As well as the Middle East crisis, the two leaders will discuss Afghanistan, where the first contingent of Royal Marines have arrived for operations against remnants of the Taleban and al-Qaida.

A commission investigating one of the biggest spying scandals in American history has concluded that the Federal Bureau of Investigation has "serious security deficiencies".

Robert Hanssen, a former FBI agent who confessed last year to selling secrets to Russia, described the intelligence agency's computer security as "pathetic", a report from the commission said.

What I did is criminal, but it's criminal negligence what they've done on that system

Former FBI agent Robert Hanssen

"Security was lax... [in] that you could bring documents out of FBI headquarters without... ever having a risk of being searched, or looked at," the counter-intelligence expert is quoted as saying.

The Commission for the Review of FBI Security Programs was set up at the request of Attorney-General John Ashcroft in response to the high-profile breach, which the investigators describe as "possibly the worst intelligence disaster in US history".

During 22 of his 25 years working for the FBI, Mr Hanssen trawled the agency's computer systems and passed documents and computer disks to the Soviet Union and Russia.

He pleaded guilty to 15 counts of espionage as part of a deal in which he was spared the death penalty on condition that he gave a full account of his spying activities.

"What I did is criminal, but it's criminal negligence... what they've done on that system," he told the commission chaired by former FBI and Central Intelligence Agency Director William Webster.

"Any clerk in the bureau could come up with stuff on that system," Hanssen said.

'Low priority'

The commission's 107-page report was published on Thursday.

"During our review of FBI security programs, we found significant deficiencies in bureau policy and practice," the investigators wrote. 

Hanssen: Described security systems as "pathetic"

"Those deficiencies flow from a pervasive inattention to security, which has been at best a low priority."

The report makes recommendations aimed at speeding the detection of employees who break ranks and minimising the amount of damage they are able to do.

Among these are increased use of polygraphs - lie detectors - and tighter restrictions on access to secret information.

The report was delivered to Mr Ashcroft on Thursday.

In a statement the attorney-general said the report "demonstrates how a trusted insider, through repeated acts of betrayal and treachery... was able to exploit deficiencies in FBI internal security systems and procedures to cause grievous harm to the national security".

South Korean officials say agreement has been reached with North Korea to restart some stalled exchanges including family reunions and economic talks. 

The news came as South Korea's presidential envoy, Lim Dong-Won, extended his trip to North Korea until Saturday to give more time to finalise a deal.

Mr Lim gave Kim Jong-il a letter from the South Korean president

These are the first public talks by the two Koreas since North Korea suspended dialogue last year.

North Korea was angered by what it saw as a hardline policy being pursued against the Communist regime by the United States, a close ally of the South. 

Mr Lim had been due to leave the North Korean capital Pyongyang on Friday but he will now stay until Saturday morning local time, said South Korean unification ministry spokesman Kim Hong-Jae.

"There were some difficulties in the talks, but we expect to be able to announce a joint statement tomorrow," Mr Kim told reporters.

The talks give fresh hope to millions of families on both sides of the border that they might one day be reunited with loved-ones they have not seen for more than 50 years, since the Korean War.

'Sense of relief'

Officials in Seoul earlier said no dates for new exchanges had been set, although they expected contacts to begin within the next few weeks. 

There have only been three limited exchanges between elderly relatives since a landmark summit between the two Korean leaders in Seoul in June 2000. 

A fourth round of exchanges due to take place last October was cancelled at the last minute by the North. 

It was angered by heightened security in the South, put in place after the 11 September terror attacks in the United States, which the North felt was targeted against itself.

Our correspondent in Seoul Caroline Gluck, says there is a sense of relief that Mr Lim's visit appears to have achieved results. 

The talks had been discussed as tough and difficult, but despite the rhetoric, it seems the North is still interested in rapprochement with the South. 

The announcement about the new peace moves came just hours after Mr Lim met North Korea's leader Kim Jong-il. 

The envoy handed the leader a letter from South Korean President Kim Dae-Jung, urging him to resume stalled ties and dialogue, not only with the South but also with the US and Japan. 

A Texan man who shot dead an Indian immigrant in the aftermath of the 11 September attacks has been sentenced to death. 

Mark Stroman told police that he killed Vasudev Patel, the owner of a petrol station in Texas, last October because he wanted vengeance for the attacks on New York and Washington. 

He is also charged with killing a convenience store owner and wounding a third man - both of them Pakistanis. 

There were several reports of revenge attacks on Muslims and members of ethnic minorities in the West following the events of 11 September.

Flying the flag

Stroman, 32, holding a small American flag, showed no reaction when the sentence was read. But as he stood up to be led out of court, he saluted in the direction of the bench and said, "Thank you, judge".

Sikhs think they were attacked because they reminded people of Bin Laden

The Dallas-area stone worker, who was convicted on Tuesday of capital murder, could have received a life prison term.

"It is the correct verdict," said Mukesh Patel, the victim's brother-in-law. "We pray for him."

In his closing arguments, prosecutor Greg Davis pointed to the victims' families as he argued for the death penalty:

"They had the American dream and believed in the ideals of this country and that's why they left their own countries," he said. "But those dreams were wiped out because this man here had another dream. His dream was to kill them all."

Stroman gunned down Patel, aged 49, on 4 October in the gas station he owned in the Dallas suburb of Mesquite, where Stroman lived. 

Muslims targeted

Stroman said he had singled him out because he looked like someone of Muslim descent.

Arab-Americans were horrified by the suicide attacks

"I'm not a serial killer. We're at war. I did what I had to do. I did it to retaliate against those who retaliated against us," Stroman said in a television interview in February.

"He is so full of hate. He said he has skin allergies against people like us. I'm happy he was found guilty so quickly by the jury," Mukesh Patel said after the conviction.

Stroman's lawyers did not dispute that he had killed Patel, but they said he did not enter the petrol station with the intention of killing the owner.

But prosecutors pointed to a surveillance tape of the murder, which they said showed Stroman was a cold-blooded killer.

Stroman has been charged with killing a Dallas-area convenience store clerk, Waquar Hassan, on 15 September. He is also suspected of shooting another store clerk, Rais Uddin, who was injured during a robbery attempt.

Both men were Pakistani.

An operation to repatriate some 350,000 Burundian refugees from Tanzania has started.

A group of 434 has arrived in the eastern Burundian border town of Kobero.

I want to eat what I have grown myself and not to have to beg

Monique, refugee

However, most of the refugees in Tanzania are afraid of going back home because of continued fighting.

Despite the inauguration of a power-sharing government in the Burundi capital, Bujumbura, last year, some ethnic Hutu-dominated rebel groups have not laid down their weapons.

Thousands of people have fled the latest outbreak of fighting around the capital in the past week.

Military escort

Around 48,000 refugees have registered to return to Burundi, the United Nations refugee agency said.

"I've spent nine years begging," said Monique, a 35-year-old refugee.

"I want to eat what I have grown myself and not to have to beg, neither I nor my children," she told the French news agency, AFP as she began her trip home.

The first convoy was given a heavy military escort as it made its way to a transit camp in Ngozi province, northern Burundi.

After a day there, the refugees will then be taken to their home villages, said Lazare Karekezi, governor of Muyinga province.

The first group of refugees is from northern Burundi, where there is less fighting than in the south.

Tanzania has complained that it is unable to host such a large number of refugees and both governments have been trying to persuade them to go back home.

Burundi's authorities have accused the Hutu rebels of encouraging the refugees to stay, so they can be used as cover for rear bases in Tanzania.

An estimated 250,000 people have been killed in a nine-year war between ethnic Hutus and Tutsis.

Thousands of people have taken to the streets of the Angolan capital Luanda to celebrate Thursday's peace deal aimed at ending nearly 30 years of civil war. 

The march, organised by the "Spontaneous Movement," a group close to President Jose Eduardo dos Santos, came as foreign governments welcomed the formal signing of the peace agreement between the government and Unita rebels.

The two signatories embraced at the ceremony

Previous peace efforts in Angola have failed, but the BBC's Justin Pearce in Luanda says most Angolans are optimistic that this latest plan will work. 

Human rights campaigners told him however, that the ceasefire was only a first step which would not automatically lead to democracy, development and justice.

And an independent journalist working in Angola, Raphael Marcques, cautioned that some people, who had benefited financially from the war, had a vested interest in maintaining the political and military tension of the past.

The agreement opens the way to reconciliation among Angolans and general elections"

Jorge Sampaio, Portuguese president

Thousands of people, all dressed in white to symbolise peace, marched through the streets of Luanda dancing, drinking and celebrating the end of the war. 

"Peace, a victory for all the Angolan people," some chanted.

A US State Department spokesman, Philip Reeker, said Washington now looked forward to the full completion of the agreement and further steps to promote national reconciliation. 

He said the US was ready to assist in those efforts. 

The agreement includes a promise by the two sides to abide by a 1994 peace accord, which collapsed almost four years ago. 

'National rebirth'

The ceasefire followed the death of Unita leader Jonas Savimbi, who was killed by government troops six weeks ago. 

It formally ends a civil war that has raged since Angola won independence from Portugal in 1975. 

The Angolan president declared the war over

Russia's Foreign Ministry congratulated Angola on its "national rebirth" and British Foreign Secretary Jack Straw called the cease-fire a "historic step forward". 

"This agreement should be the start of a sustainable political process through negotiation and dialogue, and no longer through violence and intimidation," he said. 

Portuguese President Jorge Sampaio said the accord "opens the way to reconciliation among Angolans and general elections".

 Ibrahaim Gambari, special representative of the United Nations in Angola, said it was a historic moment and promised the UN would continue its support for Angola's peace plan.

Unita commitment

Unita chief of staff General Geraldo Abreu Kamorteiro and the head of Angola's armed forces, General Armando da Cruz Neto, signed the agreement in the Angolan parliament building.

On Friday, they began the work of demobilising Unita's 50,000 fighters and reintegrating many of them into the national security forces.

Millions have been displaced by the years of fighting

Some Angolans are encouraged by the fact that the process was conducted entirely by Angolans themselves, rather than by foreign mediators. 

Others believe that Jonas Savimbi was the principal driving force behind the war and that with him now dead, the chances of peace are better than ever before. 

Some observers say Unita's army has been all but destroyed in the last few months.

Unita fighters have been arriving in Luanda, saying that they deserted the rebel force because they had nothing to eat.

Madagascar's self-declared president, Marc Ravalomanana, has said the country is in "a state of war" after months of political division in the Indian Ocean island.

He issued a "call to the Malagasy people" to fight those blocking what he believes is his rightful claim to lead the country.

People of bad intent have declared war on the Madagascan nation

Marc Ravalomanana

Mr Ravalomanana controls the capital, Antananarivo, but supporters of incumbent President Didier Ratsiraka have established a rival power-base in the port city of Tamatave and imposed an economic blockade.

Mr Ravalomanana's rallying cry - made in a televised address - marks a dramatic change of tone after months of generally peaceful demonstrations and political stand-off.

'Enemies of the nation'

"People of bad intent have declared war on the Madagascan nation with the help of a few military men," he said.

"They are starving the people by erecting roadblocks and destroying bridges.

"We declare that these people are enemies of the nation. Henceforth, we're going to track them down wherever they are."

Mr Ravalomanana urged the army to help lift the blockade and to rebuild bridges which have been attacked in areas including Fianarantsoa.

He urged active and reserve members of the security forces to join a "national security council".

Flanked by members of his government and about 40 senior armed forces officers, he warned that "those who fail to heed this call will be considered rebels".

 "The country is in danger and needs all its children to defend it," he said.

Increasing tension

Mr Ravalomanana says he was cheated out of victory in last December's election.

Official results give neither him nor Mr Ratsiraka the 50% of the vote needed for outright victory and a run-off has been scheduled for later this month.

Mr Ravalomanana has refused to take part.

Apart from a few serious clashes which claimed the lives of several people, the showdown dividing the nation has been largely peaceful, though increasingly tense since Mr Ravalomanana declared himself president on 22 February.

Most members of the army have backed Mr Ravalomanana, government offices have been taken over and rivals installed as ministers while the population carry on as usual.

 

By Dr David Whitehouse  BBC News Online science editor

Scientists have found "intriguing" new evidence that may indicate there is life on Mars.

An analysis of data obtained by the Pathfinder mission to the Red Planet in 1997 suggests there could be chlorophyll - the molecule used by plants and other organisms on Earth to extract energy from sunlight - in the soil close to the landing site.

Researchers stress their work is in a very preliminary state and they are far from making definite claims. 

Even so, the work is attracting much attention in the scientific community and will come under intense scrutiny when it is presented to an astrobiology conference in the US next week.

Chlorophyll on Earth

A pigment found in plants, some algae, and bacteria that allows these organisms to catch sunlight  This energy is used to drive photosynthesis, a process that converts carbon dioxide and water into the simple sugar glucose  Photosynthesis is the starting point for nearly all life on Earth  It is the great abundance of chlorophyll in leaves and other tissues that makes plants appear green

Dr Carol Stoker, from the American space agency's (Nasa) Ames Research Center, confirmed the findings to BBC News Online but cautioned that they were "not ready for the big time".

Early data

Mars Pathfinder mission touched down in the Ares Vallis region of Mars in July 1997. It took many images of the surrounding area and released a small rover to sample rocks.

A detailed analysis of the images of the landing site now reveals two areas close to Pathfinder that have the spectral signature of chlorophyll.

According to experts it might be highly significant - or could be just a patch of coloured soil. 

Dr Stoker's team scrutinised the so-called Superpan, which is a high-resolution, highly processed series of superimposed images produced by Pathfinder's camera.

It is a multispectral panorama of the landing site recorded in 15 regions of the spectrum, and contains a wealth of information about rock types, colours and textures.

Sojourner: A rover was used on the mission to take a closer look at the surroundings

Knowing the spectral signature of chlorophyll, the researchers wrote a computer program that systematically scanned the Superpan for any pixels of interest.

Specifically, the program looked for the spectral signature associated with red light absorption by chlorophyll.

Previous searches for evidence of chlorophyll in Pathfinder's pictures were carried out shortly after it landed.

Some tentative indications were seen but they were later dismissed as "possible image misregistration".

Two patches

In Dr Stoker's study six regions of the Superpan matched positive for the chlorophyll signature.

For each of the regions, a full spectrum was plotted out and their exact position in the Superpan was then carefully examined. 

All of the detections occurred close to the camera. This is to be expected say the researchers, as these are the areas where the camera has the highest sensitivity and resolution.

Close examination revealed that four of the cases occurred on the Pathfinder spacecraft itself. But two regions showed a chlorophyll signature in the soil around Pathfinder.

Given the controversial nature of their findings and the early stage of the research, the scientists want to hold back any claims about what they may have found until they have done more work and prepared a detailed paper for submission in a scientific journal.

The Italian Government has rejected allegations of judicial interference levelled at senior Italian politicians by the United Nations in a recent report.

In Italy, the independence and autonomy of the judges is unassailable

Roberto Castelli Justice Minister

Justice Minister Roberto Castelli said that even if politicians wanted to meddle, the independence and autonomy of judges was so deeply rooted in Italy's "judicial culture" to render any such attempts impossible.

A preliminary report from the UN released on Thursday said judges and prosecutors had "reasonable cause" to feel their independence was being threatened by leading politicians. 

It especially highlighted the continual delays in the corruption trials of the Italian Prime Minister, Silvio Berlusconi, calling them detrimental to the integrity of the justice system.

Government control

Berlusconi's trial has been delayed many times

Judges in Italy have accused the government of trying to introduce reforms that will allow the government to exert more control over prosecutors.

They have also complained that the government has been delaying corruption trials against Mr Berlusconi.

There are four cases pending against Mr Berlusconi involving various branches of his vast business empire. The charges cover false accounting, tax fraud and bribing judges. 

Mr Cumaraswamy said that one case was postponed because the former Defence Minister, Cesare Previti, repeatedly asked for a hearing to be delayed because of parliamentary obligations. 

Speaking at the Palace of Justice in the city of Trieste on Friday, Mr Castelli acknowledged that Italian trials tended to be lengthy, but said that this was the case for all defendants.

He added that it was a problem which needed to be addressed.

Despite his criticisms Mr Cumaraswamy said he did not believe that the overall independence of the judiciary had been destroyed.

"Once the root causes are removed and mutual trust restored, the tension will ease and judicial independence will triumph and will be respected by all," he said.