A Palestinian gunman crawled under a security fence at this communal farm, burst into a home and shot dead a mother and her two children as she was reading them a bedtime story. The gunman then killed two more Israelis before escaping in the dark.

The Al Aqsa Martyrs Brigade, a militant group loosely affiliated with Palestinian leader Yasser Arafat's Fatah movement, claimed responsibility for the attack. Foreign Minister Benjamin Netanyahu renewed his call for expelling the Palestinian leader, a move Prime Minister Ariel Sharon so far has resisted.

Terrified residents at Kibbutz Metzer spent the night huddled in their homes, fearful the gunman was still among them. By daybreak Monday, Israeli security forces said the attacker had fled, apparently to the nearby West Bank.

The attack raised tensions in advance of a visit this week by U.S. envoy David Satterfield, who plans to discuss a U.S.-backed plan aimed at restarting Mideast peace negotiations.

The shooting rampage began just before midnight Sunday several hours after a car exploded near the farm, killing its two Palestinian occupants in what police believed was a failed suicide bombing.

"We have a mother and her two children ... who are no longer with us, and they are victims of a war that has no end," Doron Lieber, a member of the farming community, told Israel Radio.

Kibbutz Metzer is inside Israel proper, but is less than a mile from the border with northern West Bank, where many Palestinian attackers have come from.

After going under the fence, the gunman reached the center of the community and entered a house where the lights were on, Lieber said.

He shot dead Revital Ohion, 34, and her two sons, Noam, 4, and Matan, 5. She was reading a bedtime story to her children when she first heard shots, which led her to call her ex-husband, Avi Ohion, relatives said.

He heard the shots on the phone, and later collapsed in tears when he learned they had been killed, the relatives said.

The gunman left the house and continued in the direction of the communal dining room where he met a couple taking a walk, Lieber said. He shot and killed the woman, while the man managed to flee. Another kibbutz resident drove up in his car and was killed by the gunman, Lieber said.

"There are no words to describe this," said Roni Cohen, the children's uncle.

After Israeli security forces allowed kibbutz residents out of their homes Monday morning, they gathered in the community's streets, crying and comforting one another.

A bullet hole had pierced the wooden door to the single-story stucco house which had been attacked. On the porch were bikes, a rabbit, a bird cage and posters of the two boys who were killed, one of them shown strumming a guitar.

The attack marked a rare instance in which a Palestinian gunmen has been able to carry out an attack on a guarded community and escape without being killed himself.

Members of the dovish community said they have had close relations with their Arab neighbors and support the establishment of a Palestinian state.

"We still have good relations (with the Arabs)," said Lieber, upset at reporters who asked him about local security arrangements.

In the afternoon village elders from nearby Israeli-Arab communities arrived in the kibbutz for a condolence visit.

Police initially said that the number of shell casings found suggested more than one gunman was involved. But David Tzur, a commander in the border police, said Monday that officials now believed only one gunman carried out the attack.

"The terrorist managed to infiltrate, massacre people ... he was shot at but unfortunately wasn't hit and it seems from all the signs he escaped," Tzur told Israel Radio.

The attack came on the same day that officials from Arafat's Fatah movement and the militant Hamas group launched talks in Cairo. Fatah officials have said they were going to demand that Hamas halt suicide bombings inside Israel. However, Hamas says it will continue attacks, as does the Al Aqsa Martyrs Brigades, which is loosely linked to Fatah.

"This attack was a message to the negotiators in Cairo that the Al Aqsa Martyrs Brigades will not stop its struggle and attacks against Israel," said a group spokesman in the northern West Bank, who gave his name as Abu Mujahid.

Earlier Sunday, not far from Kibbutz Metzer, a car exploded and killed the two Palestinian occupants just as suspicious Israeli police moved to stop the vehicle. It was not clear whether the Palestinians detonated the bomb intentionally or by accident, police said.

The car explosion was one of three instances Sunday in which Israeli authorities said they managed to prevent a planned suicide attack.

Throughout the West Bank, Israeli troops have been in or near Palestinian cities for nearly five months, imposing curfews and tough restrictions on Palestinian movements as part of an effort to keep militants from launching attacks.

Arafat has condemned suicide bombings, but says his security forces can't function with the Israeli troops currently controlling Palestinian areas.

Several hours after the kibbutz shooting, Israeli helicopters fired rockets into a large car repair shop in downtown Gaza City, witnesses said. The shop was empty at the time of the attack shortly. There were no reports of casualties.

An army spokesman said an Air Force helicopter fired four missiles at the shop, suspected of housing a weapons-making workshop.

Meanwhile, Israel and the Palestinians were preparing written responses to a U.S.-backed peace initiative that calls for a provisional Palestinian state by 2003 and a permanent state in 2005.