The Israeli military would say only that an operation was in progress in the area. Military sources, speaking on condition of anonymity, said the goal was to stop the firing of homemade rockets from the area. 

The operation came as Israeli and Palestinian officials planned for a meeting between their prime ministers, the first summit in nearly three years, set for Saturday night. 

Israeli forces were in control of Beit Hanoun, a town in the northeast corner of Gaza, closest to Israel, witnesses said, and tanks moved to surround the nearby town of Beit Lahiya and the Jabaliya refugee camp between Beit Lahiya and Gaza City. Israel cut off the supply of electricity to the area, they said. 

Witnesses said about 70 armored vehicles were involved in the incursion. They said soldiers with loudspeakers instructed Palestinians to stay in their houses. There were no immediate reports of clashes or casualties. 

Palestinian militants use the area to fire Qassam rockets at the Israeli town of Sderot, less than a half-mile away from the fence dividing Israel and Gaza. Several rockets were fired Wednesday, and on Tuesday, a rocket set a fire in the town, slightly injuring three Israelis. 

Despite the upcoming summit, a senior Palestinian official said that Prime Minister Mahmoud Abbas would not crackdown on militants until his Israeli counterpart accepts the "road map" peace plan. 

Yet, in a sign regional peace moves might be starting, the Israeli and Qatari foreign ministers met in Paris in the first public meeting at that level between the two countries, which do not have diplomatic relations. Israeli Foreign Minister Silvan Shalom said he hoped the meeting would "give courage to additional Arab countries" to forge ties with Israel. 

Prime Minister Ariel Sharon and Abbas plan to meet Saturday night at Sharon's residence in Jerusalem, officials on both sides said. On Sunday, Sharon flies to Washington for a meeting on the road map with President Bush. The plan was drawn up by the Quartet - the United States, Russia, the United Nations and European Union. 

The Palestinian official, who spoke on condition of anonymity, said Abbas' goal will be to persuade Sharon to drop demands for changes in the peace plan and begin carrying out Israel's obligations. 

He said that until Israel formally accepts the plan, the Abbas government will not carry out its side of the bargain, the central part of which is a crackdown on Hamas, Islamic Jihad, the Al Aqsa Martyrs' Brigades and other violent groups. 

U.S. and European officials have been pushing the two sides to begin implementing the plan, which starts with an end to 31 months of violence, a freeze on Jewish settlements in the West Bank and Gaza and Israeli pullbacks from West Bank towns and cities. 

Later stages include a Palestinian state with provisional borders and negotiations on final borders, the return of refugees and the status of Jerusalem - claimed by both sides as capital. 

Israel wants Palestinian attacks to end before it embarks on the plan. On Wednesday an Israeli government official said Sharon believed Israel needed to take no action until after a serious Palestinian crackdown on terrorism was underway. 

The official, speaking on condition of anonymity, said Israel hoped the Sharon-Abbas summit would lead to a meeting between Israeli Defense Minister Shaul Mofaz and Mohammed Dahlan, the Palestinian Cabinet minister in charge of security. 

The summit will be the first since then-Israeli premier Ehud Barak met Palestinian leader Yasser Arafat on Sept. 25, 2000, days before the current violent conflict broke out. It will be closed to reporters. 

On Sunday, Sharon plans to fly to Washington for a meeting on the road map with President Bush. 

In a visit earlier this week, Secretary of State Colin Powell failed to gain Israeli acceptance of the road map or any concessions on the settlements - an issue Powell said would be discussed in Washington. 

Meanwhile, Sharon has come under criticism in Israel as well for stalling on the peace plan. 

In a Cabinet meeting Tuesday, Justice Minister Yosef Lapid argued with more hard-line ministers, saying the government soon would have to remove illegal West Bank outposts, Israeli radio reports said. 

And the Haaretz newspaper wrote in an editorial that Sharon's recent actions and statements show that he "has yet to give up the vision of the settlements and the creeping annexation of the West Bank," and charged that "Sharon refuses to make any significant Israeli gesture" to help implement the road map.