Palestinian gunmen opened fire Friday on two Israeli cars near a Jewish settlement in the southern West Bank, killing four people and injuring three others, the army and rescue officials said.

The attack took place hours after Israel sent tanks and troops into Gaza City in its first operation since a heavily criticized bombing attack there killed a Hamas leader and 14 other Palestinians, nine of them children.

The two cars were traveling southeast of the Palestinian city of Hebron, near the Jewish settlement of Carmel, when they came under fire, settler spokesman Yehoshua Mor-Yosef said.

Three of the slain settlers were members of the same family who were on their way to spend the Jewish Sabbath with friends in a nearby settlement, Israel Radio said.

Israel TV said the gunmen, from the nearby Palestinian town of Yatta, had waited outside their car and opened fire on the first vehicle, killing two adults and a 15-year-old.

The gunmen fired on the second car as it drove by, wounding the driver, who managed to keep driving for a while until he stopped and died. Three people were injured in that attack, Israel TV said.

The army, which confirmed four people were killed, said troops were searching the area.

There was no immediate claim of responsibility. Settlers in the West Bank have been targets of dozens of shooting attacks during 22 months of fighting, most recently last week, when militants ambushed an armored bus near the settlement of Emmanuel, killing nine people.

Several Palestinian groups have vowed to seek revenge on Israel for its airstrike earlier this week on Gaza City which killed Hamas military commander Salah Shehadeh as well as the civilians.

David Baker, an official in the office of Prime Minister Ariel Sharon, said Friday's attack was "graphic proof of the extent of Palestinian terror and how totally devoted they are to killing innocent Israeli civilians.

"Israel is resolved to rid itself of the noose of terror hanging over us," Baker said.

Earlier Friday, a Palestinian man was shot and killed in the West Bank as he stood in his kitchen in Qalqiliya, Palestinian security officials said. They said Israeli soldiers searching houses in the area had fired live ammunition, and that the man had been hit in the head. The army said it was checking the report.

Before the shooting attack, Israeli and Palestinian officials had said they planned to hold talks early next week on improving the Palestinian economic situation and easing restrictions in the West Bank, where Israel controls seven of the eight main Palestinian towns and cities. After its air strike Tuesday, Israel pledged to release some funds it is holding from the Palestinian Authority and to lift curfews.

Raanan Gissin, a Sharon spokesman, said success of the meetings depended on Palestinian efforts to stop attacks against Israel.

In Lebanon, a TV station run by Hezbollah guerrillas said another faction affiliated with Fatah was threatening to kill Sharon and other top leaders. The leaflet from the "Popular Army Front" listing the names apparently originated in Lebanon and was not circulated in the West Bank, Palestinians said.

In the nighttime Gaza raid, witnesses said seven tanks and a bulldozer flattened a small Palestinian intelligence position and a metal workshop. Soldiers then blew up another workshop in a blast that could be heard all over the city.

Gunmen fired at the Israelis, and two Palestinians were wounded in the exchange, they said.

Israeli tanks have on at least two occasions entered the fringes of Gaza City in the past 22 months of fighting. The overnight raid was believed to be the deepest they have entered into the city, however.

The Israeli military said soldiers destroyed three buildings containing rocket workshops. "During the past few days, dozens of mortar shells and Qassam rockets were launched toward army posts and Israeli communities inside and outside the Gaza Strip," an army statement said.

After noon prayers, about 3,000 Palestinians, many of them Hamas gunmen, marched through the Jabaliya refugee camp on the edge of Gaza City vowing revenge on Israel for the attack that killed Shehadeh.

"The Hamas reaction will be equal to the Zionist crime," Hamas official, Abdul Aziz Rantisi, told the crowd, which included five veiled women who said they were relatives of Shehadeh.

Israeli officials continued to justify the airstrike while apologizing for the civilian casualties. But denunciations continued.

Palestinian leader Yasser Arafat, speaking with reporters Friday in Ramallah, urged the United States to use its influence on Israel to prevent future attacks, and dismissed claims by Israel's defense minister that he didn't know so many civilians would be killed.

"He cannot fool us and the world," Arafat said.

In Washington, Secretary of State Colin Powell said his government was reviewing Israel's use of U.S.-made weapons in the wake of the air strike. Israel had no comment, but an official, speaking on condition of anonymity, said Israel had nothing to hide.

Israeli Defense Minister Binyamin Ben-Eliezer defended the decision to kill Shehadeh, commander of the Hamas military wing which has claimed responsibility for hundreds of attacks against Israelis.

Speaking to his Labor party, Ben-Eliezer claimed Shehadeh was planning a "mega-terror" attack inside Israel, "perhaps the biggest Israel has ever seen, a truck with a ton of explosives that was intended to shock the people of Israel and cause hundreds, hundreds of dead."