Israel killed the top commander of Hamas's military wing and three other activists in a helicopter missile strike on a car in the Gaza Strip  on Saturday, drawing vows of revenge from the resistance Islamic group. Ibrahim al-Maqadma, 51, was a founder of Hamas and was believed to be the top commander of its military wing, which has waged a resistance bombing campaign against Israel since the signing of interim peace accords with the Jewish state in 1993.

Four Israeli helicopter gunships swooped out of the sky and blasted a car in which Maqadma and three other activists were driving, turning it into a heap of charred, smoking wreckage and scattering body parts along the Gaza City road, witnesses said.

Hamas's military wing ordered its cells to take revenge, including by killing Israeli political leaders. The Palestinian Authority  strongly condemned Maqadma's "assassination" and said it would hold Israel responsible for its consequences.

Hours after the missile strike, Palestinian President Yasser Arafat  nominated Mahmoud Abbas, a senior PLO official, as prime minister, a step on the way to major reforms of the Palestinian Authority demanded by international mediators.

Maqadma was the most senior Palestinian activist Israel has killed since the Palestinian uprising began in September 2000 after a deadlock in peace talks.

The missile strike was the latest move in a wave of violence that has rocked Israelis and Palestinians, frustrating U.S. efforts to calm 29 months of bloodshed as it tries to rally international support for a possible war on Iraq .

Thousands of Palestinians at Muqadma's funeral urged Hamas's Izz-el-Deen al-Qassam military wing to carry out revenge attacks.

"The Qassam brigades will cut off a 100 heads in return for the death of our martyr. Our words will soon be translated into action," Hamas supporters chanted through loudspeakers.

"There is a call and an order from Hamas's political leadership to the Qassam brigades to target Israeli leaders," senior Hamas leader Abdel-Aziz al-Rantissi told mourners.

Hamas leaders said the killing was a major loss for the group. "They've crossed the red line," said Ismail Haniyah, a senior leader of Hamas, which is sworn to Israel's destruction. "They have opened a new battle field," he said.

HAMAS THREATENS ISRAELI LEADERS

An Israeli security source described Maqadma as "a key decision maker in Hamas" and said he had been the top leader of the group's military wing for the past two decades.

Hamas sources said Maqadma was the brains behind Hamas's armed wing and its top commander, though Hamas political leaders said he was not involved in military activities.

Palestinian cabinet minister Saeb Erekat told Reuters: "We condemn in the strongest possible terms the new assassination in Gaza and we hold the Israeli government fully responsible for the consequences of this act."

On the political front, Arafat nominated Abbas, who has kept a back channel open to Israel during the fighting, as the first Palestinian prime minister, a post he is creating under intense Western pressure.

Arafat did not set a date for the appointment or spell out Abbas's powers. Abbas, known by his nom de guerre Abu Mazen, has said he will accept the job only if he is given significant powers.

Violence has escalated in recent days. On Wednesday, a Palestinian resistance bomber killed 15 people on an Israeli bus which a top Hamas leader said was an attack by the group.

Hours later, 12 Palestinians were killed in an Israeli raid in Gaza and on Friday Hamas resistance men killed two Jewish settlers when they infiltrated the West Bank settlement of Kiryat Arba and opened fire on settlers gathering for prayers.

The resistance men shot dead a husband and wife before holing up in a religious seminary where they were killed by occupation soldiers.

Shortly afterwards, two Palestinian activists tried to infiltrate the neighboring Negohot settlement and were killed in a gunbattle with occupation soldiers, an occupation army spokesman said. One of the resistance men detonated an explosive belt around his waist, he said.

A leaflet handed out in the Palestinian-ruled part of Hebron said Hamas claimed responsibility for the Negohot attempt in "revenge for the massacres of Palestinians, especially in Gaza."

Most Palestinians consider settlements on occupied land as legitimate targets for attack. The international community views the settlements as illegal, but Israel disputes this.

On Friday, the occupation army seized part of the northern Gaza Strip in what the occupation army called an open-ended campaign to thwart Hamas rocket attacks on Israel. Gaza has been a key flashpoint during the uprising, in which at least 1,918 Palestinians and 722 Israelis have been killed.

PHOTO CAPTION

The wreckage of a car in which four Hamas activists were killed in Gaza city is turned over by a crowd gathered at the site March 8, 2003. An Israel helicopter gunship fired missiles at the car, killing Ibrahim al-Maqadma, 50, a top Hamas leader and a founder of the group with other three activists . (Jose Manuel Ribeiro/Reuter