An Aljazeera correspondent said armed clashes had erupted between resistance groups and Israeli occupation forces who besieged suburbs of the city and launched a search-and-arrest campaign.
The Israeli raid came as US Secretary of State Condoleezza Rice met Prime Minister Ariel Sharon on Friday aiming to safeguard Israel's planned Gaza pullout after a flare-up of violence.
Rice began the visit, her third to the region this year, pressing Israel and the Palestinians on Thursday to coordinate the mid-August withdrawal from the occupied strip.
The hastily arranged trip followed a surge of Israeli-Palestinian bloodshed and mass protests by Jewish extremists opposed to Sharon's Gaza plan, developments that have aggravated tensions and complicated the withdrawal.
Keeping a low profile, Rice flew by helicopter to Sharon's sprawling Sycamore Ranch in southern Israel for closed-door talks. She was due to meet Palestinian President Mahmoud Abbas on Saturday in the West Bank city of Ram Allah.
Sharon reaffirmed his intentions
to keep West Bank settlements
"I look forward to talking with both the Israelis and the Palestinians about the need for tight coordination," Rice said after arriving on Thursday.
"I also look forward to talking about the need to resist any
efforts by terrorists to destroy this moment of hope," she said.
Rice praised a pledge by Abbas to curb resistance fighters, but Sharon was expected on Friday to urge her to put more pressure on the Palestinian Authority to crack down on armed groups as required under a US-sponsored road map peace plan.
The two sides have done little in the past few weeks to coordinate on Gaza amid the worst flare-up of violence since a truce was declared in February.
Rightists have held protests
against the Gaza withdrawal
Israel insists on calm for its evacuation of 21 settlements in Gaza and four of 120 enclaves in the West Bank under a plan Sharon has billed as disengagement from conflict with the Palestinians.
A senior US official denied Israeli media reports that Rice had proposed a summit to bring together Israel and Arab
countries after the pullout, saying the US focus after the
withdrawal would be on revitalising the road map.
Sharon settlement pledge
Overall prospects for renewed peacemaking remain bleak.
Sharon reaffirmed on Thursday that Israel intends to keep large Jewish settlement blocs in the West Bank, where the vast majority of Israel's 240,000 settlers live.
His pledge is certain to fuel Palestinian fears that as Israel leaves Gaza, it will cement its hold on much of the West Bank. The Palestinians want both the Gaza Strip and West Bank -
The separation wall came under
fire at the United Nations
together home to 3.76 million Palestinians - for their state.
Palestinian officials said a long-standing call for a freeze on settlement building would be high on the agenda at their talks with Rice. Israel has failed to meet its road map requirements on halting settlement expansion.
Sharon's deputy, Ehud Olmert, raised the prospect on Thursday of bringing forward the mid-August start date for the evacuation of Jewish settlers to avoid further mass protests to disrupt it.
But a senior Israeli official said such a move was unlikely due to political and logistical obstacles.
Elsewhere, Israel came under fire in the UN Security Council on Thursday over its West Bank separation barrier.
The council wrapped up a day-long debate on rising tensions in the Middle East as Israel said its Gaza pullout, due to begin in mid-August, could be moved forward in a bid to avoid further protests by opponents.
But the session was interrupted by a clash over Israel's 10 July decision to approve a revised route for the West Bank separation barrier around east Jerusalem that is to be completed by 1 September.
Israeli recently rerouted the wall
in East Jerusalem
Somaia Barghouti, the representative of the Palestinians' UN observer mission, called the move "a grave development and a flagrant challenge to the international community".
The path of the revised barrier route will cut through two Palestinian neighbourhoods, leaving about 50,000 Palestinian residents of annexed east Jerusalem on the West Bank side of the barrier.
"The Israeli government is exploiting the desire of the international community to see the success of the withdrawal from Gaza to accelerate the creation of facts on the ground, to impose a fait accompli which is illegitimate and based on the attempt to undermine the possibility of creating an independent, sovereign Palestinian state" along the 1967 borders, Barghouti said.