OCCUPIED JERUSALEM, 4 October — Israeli forces killed six Palestinians in the Gaza Strip yesterday in retaliation for a raid on a Jewish settlement as a shaky Middle East cease-fire agreement threatened to collapse.

Violence also spread to the West Bank, where Palestinian gunmen fired into a crowd of thousands of Jewish worshippers at the Tomb of the Patriarchs in the divided city of Hebron, wounding two Israeli women, one seriously, the army said.

The latest bloodshed left an already shaky truce in tatters, dealing another blow to Washington’s efforts to end the fighting as it tries to draw Arab nations into an anti-terror alliance after last month’s attacks on New York and Washington.

Israeli-Arab lawmaker Ahmad Tibi said Israel had responded by calling off talks scheduled for yesterday between Foreign Minister Shimon Peres and senior Palestinian negotiators as well as security talks set for later this week.

The Israeli Army sent tanks and bulldozers rolling into a Palestinian-ruled area of the Gaza Strip yesterday, killing four policemen and two others.

The raid was in retaliation for the overnight attack on the heavily guarded Jewish settlement of Alei Sinai, which killed two people.

Palestinian Information Minister Yasser Abed Rabbo accused Israel of using any pretext to undermine the cease-fire that was reaffirmed a week ago during talks between Palestinian President Yasser Arafat and Peres.

A 19-year-old Israeli woman soldier who lived in Alei Sinai and her friend were shot dead during the attack — condemned by the Palestinian Authority — on Israel’s northernmost settlement in Gaza. Fifteen people were wounded. Israeli troops killed the two attackers, members from the Hamas group.

Adding to tensions in the region, Hezbollah guerrillas fired mortar rounds and missiles at two Israeli outposts in the Shebaa Farms area along the Israel-Lebanon border, Israeli officials said. No casualties were reported.

Palestinian officials accused the Israeli Army of attacking Palestinian civilians. “Its aim is to continue the assault on Palestinian people because the coalition of evil between Sharon and his army leadership has one program, which is war, and they want to avoid any political solution,” Abed Rabbo said.