An Israeli air force F-16 blew up a house belonging to a Hamas leader early today, killing at least 11 people including his wife and three children, Palestinian officials said.
Sheik Salah Shehada, founder of the military wing of Hamas, known as Izzadine el-Qassam, was hit, Israelis and Palestinians said, but it wasn't clear how seriously.
The Gaza City missile strike, which doctors said injured more than 100 people, came at a delicate time in Palestinian-Israeli relations with the sides trading ideas to relieve tensions in the West Bank. But the attack appeared likely to derail the efforts as Hamas threatened revenge.
Shehada's wife and three of their children were killed, Hamas spokesman Ismail Haniyeh said.
Announcements on loudspeakers in Gaza said Shehada was wounded. And the Israeli military confirmed that Shehada was the target and said he was hit. But his condition remained in doubt hours after the airstrike.
"We don't have any clear information," Haniyeh said at Gaza's Shifa hospital, where the casualties were taken. "Some sources said he is alive. Some sources say he had the honor of becoming a martyr."
In its statement, the Israeli military said that Shehada was behind "hundreds of terror attacks in the last two years against Israeli soldiers and civilians."
Hamas threatened to strike back. "We will avenge the blood of the martyrs," it said in a statement. The Palestinian Authority denounced the strike and called for international intervention to "stop these massacres."
The Hamas military wing has claimed responsibility for dozens of attacks against Israelis during nearly two years of fighting, including many suicide bombings. Also, Hamas has been behind almost daily mortar attacks on Jewish settlements in the Gaza Strip.
The airstrike followed two Palestinian attacks last week that put an end to a monthlong respite in fatal Palestinian strikes against Israelis, the longest such period since the current round of violence began in September 2000.
Monday, the two sides appeared to be moving toward easing months of tensions. Israeli Foreign Minister Shimon Peres had said that the army was prepared to withdraw from two West Bank towns, Bethlehem and Hebron, as long as they remained quiet and if the Palestinians assumed control of security.
A top Hamas member said the group was considering stopping attacks if Israel withdraws, and an Israeli official said the government was looking into resuming security cooperation with the Palestinians after it pulls out.
However, more hawkish elements of Israel's government expressed skepticism about reaching a deal that would hold. They suggested that Israel would remain in the Palestinian towns for considerable time, even until Palestinian leader Yasser Arafat was no longer in power.
Also Monday, Israeli police reopened the university offices of the leading Palestinian official in Jerusalem, Sari Nusseibeh. Police closed his office two weeks ago, alleging that Nusseibeh, the president of Al Quds University, had violated peace accords by engaging in Palestinian political activity in Jerusalem.
Nusseibeh, who is the chief representative of the Palestine Liberation Organization in Jerusalem, said he signed a document Monday agreeing not to use the premises for political activity. However, he said he'd conduct his PLO activity elsewhere.
The emerging divisions in Prime Minister Ariel Sharon's government over the issue of a West Bank withdrawal came after Peres and Cabinet member Dan Naveh, a member of Sharon's hawkish Likud party, met Saturday in a Tel Aviv hotel with a Palestinian delegation headed by Cabinet Minister Saeb Erekat.
The meeting was attended by the new Palestinian interior minister, Abdel Razak Yehiyeh, who is responsible for security in the Palestinian territories.
The Israeli daily Haaretz reported Monday that Yehiyeh outlined a proposal to resume security cooperation with Israel after Israeli troops withdraw. Security cooperation, in which the sides share information and act jointly where possible to prevent attacks, halted after fighting erupted in September 2000.
Palestinians would confiscate illegal weapons and arrest militants, Haaretz reported. In return, the newspaper said, Israel would free prisoners arrested in the fighting, end its strikes on Palestinian targets and end its "targeted killings" of militants, which the Palestinians call assassinations.
The proposal was similar to a deal worked out last summer by CIA director George Tenet that was never implemented as the violence escalated.
But Ranaan Gissin, Sharon's spokesman, said Israel wouldn't make concessions before the Palestinians ended attacks.
"There will be no concession on security until we see them take steps," he said, adding that as a first move the Palestinians should assume security control in the Gaza Strip to show that they were willing to crack down on militants.
Naveh said he doubted the Palestinians would crack down. He suggested the Israeli army would remain in the West Bank until the Palestinian leadership is replaced.