More than 4,000 Palestinians have been detained during Israel's offensive in the West Bank, the army says.

The figure - which has doubled in the past 24 hours - reflects the growing pace of the military campaign, correspondents say.

The mission is still on... I'm looking forward to the opportunity to meet with Prime Minister Sharon and with Chairman Arafat

US Secretary of State Colin Powell

US Secretary of State Colin Powell, who is in Amman for talks with Jordan's King Abdullah, arrives in Jerusalem later on Thursday to try to secure a ceasefire and implement a step-by-step plan leading both sides back to peace talks.

However, Prime Minister Ariel Sharon has told Washington that it should not put Israel under pressure to end its military offensive against Palestinian militants.

An Israeli army spokesman said most of the Palestinians rounded up during the offensive were released shortly afterwards, once their identification had been checked. 

Click for a detailed guide to the West Bank operation

Detainees were held at an army base in the West Bank and included more than 100 men on Israel's list of most wanted suspects.

They could be held for up to 18 days before being taken before a judge. 

Tough mission

The American Secretary of State is due to meet Mr Sharon on Friday, and the Palestinian leader Yasser Arafat on Saturday.

Speaking after a phone call with Mr Sharon, Mr Powell stressed the need to get into political talks however long the current offensive lasts.

	Israel's West Bank operation

However he did not repeat the US call for an immediate Israeli withdrawal from the West Bank. 

The BBC's Jonny Dymond in Jerusalem says no one in Israel is expressing much optimism about Mr Powell's visit.

In the hours before his arrival, Israeli troops occupied three more areas in the West Bank and withdrew from several others.

Tanks and troops entered the town of Bir Zeit, the refugee camp of Ein Beit Elma near Ramallah and Daharyeh village near Hebron, and are reported to be carrying out house-to-house searches.

In Bir Zeit, troops reportedly took over the police station and witnesses said soldiers ordered students out of their dormitories at Bir Zeit University, detaining several of them. 

Overnight Israeli forces retreated from Yatta, Qabatiya and Samua - four days after they swept into the autonomous areas as part of Operation Defensive Shield.

They say they have withdrawn from 24 small towns and villages altogether.

'Finishing the job'

On a visit to the West Bank town of Jenin, the scene of some of the fiercest fighting, the Israeli prime minister rebuffed calls for Israel to halt its offensive.

"We will continue to operate against the terror and its infrastructure," he said.

Mr Sharon said Israel was engaged in a war for its survival and the army had to "finish the job".

Jordan's King Abdullah II helped the Palestinian aid effort

Israel took control of Jenin on Wednesday after about 300 Palestinians, including armed fighters, surrendered to Israeli troops.

Unconfirmed reports on Thursday said another group of gunmen had given themselves up in Jenin.

Twenty-eight Israeli soldiers and more than 100 Palestinians were killed in eight days of fighting in the town, which has been declared a closed military zone.

On Thursday the BBC's James Reynolds managed to get into Jenin to the outskirts of the refugee camp, witnessing empty streets, damaged buildings and rubble on the road before being told to stop filming and leave by Israeli soldiers. 

Bethlehem standoff

Troops also remain in Ramallah, Nablus and Bethlehem - where a stand-off continues around the Church of the Nativity, the traditional birthplace of Jesus Christ. 

There are still more than 100 armed men inside the church, and the Israeli army says that among them are 30 militants on its wanted list.

The standoff at Manger Square continues

A suggestion by Christian leaders that the gunmen be granted safe passage to the Gaza Strip has been rejected by the Israelis, one of the negotiators told the BBC.

The BBC's Caroline Hawley said she saw black smoke billowing from the direction of Manger Square after hearing a series of explosions.

There was no immediate comment from the Israeli army, but Palestinians living nearby said that soldiers had blown up several cars on a nearby street. 

For a second day, the Israel army has had a surveillance balloon hovering over the compound. 

In Jordan, King Abdullah II and Queen Rania helped load food and medicines onto five helicopters due to fly the aid to the West Bank Palestinians on Thursday.

At least five people have been killed by a powerful explosion at an ancient synagogue on the Tunisian island of Djerba.

The head of the local Jewish community, Peres Taraboulsi, said: "I think it's an accident, and that it has no link to the situation in Israel". 

A truck filled with natural gas crashed into a wall surrounding the synagogue, he said, identifying the dead as the truck driver and four Germans.

However, Israeli foreign ministry spokesman Emmanuel Nachshon told BBC News Online that "all the evidence points to a truck bombing and not an accident".

'Bad for tourism'

The blast was heard at least five kilometres (three miles) away from the famous Ghriba synagogue, Tunisia's official news agency said.

German tour operator TUI said 29 of its guests, who were on a bus trip to the synagogue, were injured. A spokeswoman for the company did not know if its guests were among those killed.

Some were treated in hospitals on Djerba, while those seriously injured were flown to the mainland.

There is speculation that it was an attack on a symbol of the small Jewish community at a time of growing anger in the Arab world over Israel's offensive in the West Bank.

Work of wonder

La Ghriba means 'the one who works wonders'  There are more than 1,000 Jews on Djerba  Ancestors believed to have arrived more than 2,000 years ago  Said to have been founded after the Jewish Exodus of 556 BC  Place of pilgrimage for Sephardic Jews, second only to Jerusalem's Western Wall  Houses unique collection of Torahs

"From the information that we are getting from members of the Jewish community there, we gather that it was an attack and not an accident," another Israeli foreign ministry official told BBC News Online.

"A truck full of explosives rammed into the wall of a synagogue - it's no coincidence that it was a synagogue, while everything is going on here in the Middle East," he said.

"It's a city of tourism - the reason the Tunisians are saying it was an accident is because they don't want to scare the tourists."

Residents also voiced fears that the synagogue had been targeted.

"Many people fear it was a deliberate attack as what is happening now in the Middle East is on everyone's mind," a member of the Jewish community told the Reuters news agency.

A Djerba resident said: "Many people are worried and most of my friends were praying that it was not a suicide attack. If it was so, Tunisia will suffer from the bad publicity."

Jewish sites in France have come under attack in recent weeks in violence linked to the Middle East.

Pilgrimage site

Ghriba, whose foundations are said to date from 586 BC, is one of Africa's oldest synagogues and is still functioning.

It attracts several thousand visitors for an annual spring festival.

The island of Djerba, off Tunisia's southeast coast, is a popular holiday destination.

It is also home to around 1,000 of Tunisia's 3,000 Jews.

The Jews of Djerba have lived quietly on the island for nearly 2,000 years in two small villages, far away from Tunisian political life and the Arab Muslim population of the mainland. 

Their forefathers fled from Jerusalem following the destruction of the Temple. 

Many Jews left Tunisia following the creation of Israel in 1948; others followed when the synagogue in the capital Tunis was burned down during the 1967 Middle East war.

The Yugoslav parliament has approved a new law that will pave the way for suspected war criminals to be extradited to the UN tribunal in The Hague.

The bill, a compromise worked out between members of the governing coalition, will only apply to suspects already indicted by the Netherlands-based court.

It can be expected that all the suspects will be handed over to The Hague tribunal by 1 May

Yugoslav Interior Minister, Zoran Zivkovic

It applies to about 20 suspects believed to be hiding in Yugoslavia and was approved in the lower house with 80 votes for and 39 against. The upper house approved it on Wednesday.

Among those likely to be handed over first are top associates of former Yugoslav President Slobodan Milosevic, who is already on trial for war crimes at the UN tribunal. 

The government has been under pressure from Washington to start extraditing suspects - the US effectively froze $40m of aid after Yugoslav authorities failed to meet a 31 March deadline to act.

Aid resumption?

Thursday's decision could clear the way for the resumption of aid payments, but the US had demanded that Yugoslavia co-operate unconditionally with The Hague.

Under the current bill anyone indicted in the future will be tried by authorities in Yugoslavia.

Djindjic says extraditions could start in three weeks

For the aid payments to begin again the US Secretary of State Colin Powell must certify the country's compliance.

Before the law was passed the Yugoslav Interior Minister, Zoran Zivkovic, who is in charge of police, said that the first extraditions could take place very soon.

"It can be expected that all the suspects will be handed over to The Hague tribunal by 1 May," Mr Zivkovic said.

Milosevic aides

That sentiment was echoed by Serbian Prime Minister Zoran Djindjic, who said the first handovers would take place within three weeks.

Kosovo co-accused

Milan Milutinovic, Serbian President  Nikola Sainovic, former Yugoslav deputy prime minister  Vlajko Stojiljkovic, former Serbian Interior Minister  Dragoljub Ojdanic, former army chief of staff

Three of four men indicted with Mr Milosevic for war crimes in Kosovo are thought to be most at risk - a former deputy prime minister, a former interior minister, and a former army chief of staff. 

Correspondents say that co-operation with The Hague is a deeply divisive issue in Yugoslavia, where many regard the court as illegal.

Mr Djindjic - who had faced tough opposition from nationalists and supporters of Mr Milosevic for advocating co-operation with the tribunal - said the law will resolve "all the problems we had with The Hague court and the American administration".