Israeli troops in jeeps swooped down on the West Bank city of Nablus early on Monday, shutting down a girls' school, a medical centre and two other facilities of a Hamas-affiliated charity, witnesses said.

Computers, documents, cash and furniture were seized, the witnesses said.

The Israeli military had no immediate comment on the Palestinian reports. But the raid appears to have been part of an intensified crackdown on Hamas in the West Bank by Israel and Palestinian President Mahmoud Abbas.

Three weeks ago, Israel and Palestinian militants in Hamas-ruled Gaza agreed to a truce. Although the ceasefire is limited to Gaza, confrontations between Israel and Palestinian fighters in the West Bank have already provoked Gaza groups to violate the agreement.

Moral crime

"We consider the Israeli decision to shut down charities that take care of families of martyrs, orphans and poor people as a moral crime," Hamas spokesman Fawzi Barhoum said in Gaza.

"It's an inhumane act against poor sectors in the Palestinian society."

In recent months, Israeli troops and Abbas' security forces have gone after West Bank charities, moneychangers, women's cooperatives, media outlets and schools with suspected ties to the militants.

Around 1am yesterday, dozens of military jeeps, two bulldozers and two trucks entered Nablus and headed for the facilities of the Solidarity charity, delivering an order to shut the facility for three years, witnesses said.

The troops shut down Solidarity's headquarters, as well as an elementary school for 160 girls and a sports club.

"The Israelis have confiscated all computers, documents, televisions and even mobile phones, from the school," said principal Fidda Draikh. "Now we need to look for an alternative place to educate these girls. We cannot leave them without a school."

"The medical centre that was shuttered bears the same name as the charity but is run by a different charitable organisation that was controlled by Hamas until its top administration was replaced last year by Abbas' government, " said its director, Dr Hafez Al Sadr.

Sadr said office equipment was smashed and computers, documents and about $6,000 in Israeli and Jordanian currency was seized. He said the centre is not connected to Hamas.

Troops also raided Nablus offices of the Palestinian Authority's ministry of religious affairs. Israel is trying to negotiate a peace deal with the Palestinian Authority and it was not clear why the ministry was targeted.

Shaikh Hassan Hilali, a ministry official, said the Israelis "have nothing to look for here. They entered the wrong place ... It's a bad sign of how they perceive peace."

Also yesterday Palestinian militants fired a mortar shell at a border crossing with the Gaza Strip, the Israeli army said.

No one was hurt in the attack on the Karni crossing, the military said.