Some of the heaviest fighting was in Nablus, the largest city in the West Bank. Palestinian sources said they had confirmed 14 Palestinians -- mostly civilians -- were killed, mainly in the Balata and Asker refugee camps. Thirty people were reported injured, but ambulances were unable to get into the area. 

Israeli troops controlled most of the city, and the Israel Defense Forces arrested a large number of people, witnesses said. 

Israel has said the campaign is aimed at destroying the Palestinian terrorist infrastructure. The campaign began after a wave of suicide bombings by Palestinians, beginning with the bombing of a crowded restaurant at the beginning of Passover that killed 26 Israelis. 

The IDF said it is holding 1,200 Palestinian suspects in connection with terrorism, and it is reopening Ktziot internment camp in southern Israel's Negev desert for those detained. 

Cross-border fighting also continued Friday between Hezbollah guerrillas in Lebanon and Israeli forces. 

U.S. Secretary of State Colin Powell will leave Sunday for the Middle East on a mission to try to get Israelis and Palestinians back to the negotiating table, Powell announced Friday. 

Echoing comments made by President Bush on Thursday, Powell called on Israel to withdraw its forces from Palestinian cities and said he hopes "the tragic situation we are seeing in the region on our television sets every day now will soon be brought to an end."

The man who chaired the international group that authored the Mitchell peace plan said Israel's military could make Powell's mission more difficult 

"The risk, of course, is that longer and deeper the incursion goes, the less likely that Secretary Powell's visit will be successful," said former U.S. Sen. George Mitchell. 

Terje Larsen, the U.N. special envoy to the Middle East, also warned that getting the Palestinians to end terror attacks is not the only goal of the international community. 

"What I do think is at the core of the problem, which we in a quartet -- that is the European Union, the U.S., Russia, the U.N. -- will have to say in the next couple of weeks, is that no cease-fire can take hold unless there are political underpinnings," Larsen said. 

After a week of being isolated in his Ramallah compound by Israeli troops, Palestinian leader Yasser Arafat met there Friday with U.S. Middle East envoy Anthony Zinni, the first international representative to see Arafat since the Israeli military campaign began. 

Zinni persuaded Arafat to form a committee of senior aides to work with him on a way out of the current crisis -- but Palestinians said Israel barred the three committee members from meeting with Zinni late Friday. 

"As we have been informed officially by the American delegation here, Mr. Sharon rejected totally for such a meeting to take place," said Muhammad Rashid, a top Arafat aide. 

Israel had no immediate comment on the matter. 

Meanwhile, between 1,800 and 2,000 pro-Arab protesters rallied in New York's Times Square chanting anti-Israeli slogans. 

In Manama, Bahrain, police clashed Friday with thousands of demonstrators who had gathered outside the U.S. Embassy to protest U.S. and Israeli actions in the Mideast.(Full story) 

In Istanbul, Turkey, nearly 4,000 demonstrators gathered outside a mosque Friday to show their support for Palestinians. 

Protests were also reported in Egypt, Lebanon, Tunisia, Saudi Arabia, Indonesia, and Jordan.