Associated Press Police officers and rescue workers examine the scene of an exploded bus on a main road near the port city of Haifa Wednesday April. A suicide bomber with explosives strapped to his body blew up the crowded bus during morning rush hour yesterday, killing at least eight people and wounding 14.

JENIN, West Bank - From a West Bank army base overlooking the scene of the deadliest fighting in Israel's 13-day-old offensive, Prime Minister Ariel Sharon yesterday delivered a blunt message: Israel will not pull back until Palestinian militias are crushed.

Despite his pledge to continue the offensive in the face of intense U.S. and international pressure to call it off, Sharon's defense ministry announced late yesterday troops were pulling out of West Bank villages of Yatta, Qabatya and Samua.

Yatta and Samua are near the southern city of Hebron, and Qabatya is near the northern city of Jenin, where some of the fiercest fighting has been reported.

Sharon's statement earlier yesterday defied increasingly impatient U.S. demands for a withdrawal from Palestinian towns - to be delivered in person tomorrow by Secretary of State Colin Powell - and came hours after an Islamic militant blew himself up on a bus in northern Israel, killing himself and eight passengers.

Speaking to cheering soldiers at a post overlooking the battered Jenin refugee camp, Sharon said he explained to President Bush that "we are in the middle of a battle" which, if abandoned prematurely, would only require another round of fighting later on.

"Once we finish, we are not going to stay here," the former general said. "But first we have to accomplish our mission." He added that unless Israel crushed the militants, the phenomenon of suicide bombings "could spread like a plague around the world."

Earlier in the day, Israel's Security Cabinet affirmed the decision to continue the offensive. By nightfall, resistance was subdued in the Jenin camp - where fighting has raged for days and where 13 Israeli soldiers were killed Tuesday in a sophisticated Palestinian ambush - and in the old town of Nablus, the largest West bank city.

Powell insisted his peacekeeping mission was not threatened by Sharon's refusal to halt the incursions. "My mission is not in the least in jeopardy," he told reporters in Spain.

Powell, who arrives in Jerusalem late today, said he intends to meet both Sharon and Palestinian leader Yasser Arafat. Sharon said Powell would be making a "tragic mistake" in meeting with Arafat, who has been confined to his Ramallah offices by Israeli forces for the past two weeks.

Still, Israel has said it would not try to prevent a Powell-Arafat meeting. Israel allowed Arafat to see several senior aides yesterday. Later in the day, the Palestinian officials met with U.S. envoy Anthony Zinni.

Sharon has branded Arafat the leader of a "regime of terror" and has suggested he would no longer do business with him. However, Powell reiterated yesterday that the United States would continue dealing with Arafat.

Palestinian Parliament Speaker Ahmed Qureia said the Palestinians would demand that Powell secure an immediate Israeli withdrawal from Palestinian areas and that U.S. mediators come up with a timetable for carrying out a cease-fire.

Israel withdrew from two Palestinian towns earlier this week, but its forces remained in four others.

In the Jenin refugee camp, dozens of gunmen holed up in a small area fired sporadically yesterday morning at Israeli troops advancing with bulldozers. A local leader of the militant group Hamas, Jamal Abdel Salam, quoted one gunman as telling him by phone: "We are in a group inside a house. They (the Israelis) are at the door and they are coming to arrest us. Take care of my family."

Later yesterday, about 300 camp residents, including armed men, women and children, surrendered to Israeli troops. An Associated Press photographer driving through the camp saw many building facades with wreckingball-sized holes from Israeli shelling. Streets were deserted, and there was no sign of Palestinian resistance.

More than 100 Palestinians are believed to have been killed in the Jenin camp, and many bodies remain in the streets. Among those reported dead was Mahmoud Tawalbeh, a 23-year-old leader of the militant Islamic Jihad group who masterminded a number of suicide bombings.

In Nablus, rescue workers yesterday retrieved the bodies of 14 Palestinians, bringing the total of dead in the city since the start of the Israeli invasion to 60. The old city of Nablus, a warren of narrow alleys, had been the scene of fierce battles for days.

On the city's outskirts, Israeli tanks and helicopters shelled the Al Ain refugee camp, damaging some homes. After daybreak, soldiers with loudspeakers called on teen-age boys and men to come out of their homes, and witnesses saw hundreds of Palestinian men sitting on the ground in front of the mosque.

And in Bethlehem, a standoff continued at one of Christianity's holiest sites, the Church of the Nativity. An Armenian monk in the compound was seriously wounded, and Israeli troops and armed Palestinians blamed each other for the shooting.

Palestinian security sources and the Israeli military also said Israelis killed the leader of the Hamas military wing in Hebron, Akram al-Atrash, in his hideout in the nearby village of Dura.

Twenty-eight soldiers have been killed in Israel's offensive, according to the military. The Palestinian Red Crescent says it has confirmed at least 128 Palestinians dead and 337 wounded, but that the toll was expected to rise significantly.

The army said it has detained more than 2,100 Palestinians, including 117 on Israel's wanted list, and confiscated nearly 2,500 rifles.

Yesterday's suicide bombing near Haifa was the fourth since Israel began its operation in the West Bank. Hamas claimed responsibility, and sources in the group identified the assailant as Ayman Abu Haija, 22, from the Jenin refugee camp. It was not clear when he left the camp.

The bomber detonated explosives strapped to his body at 7:15 a.m., moments after boarding the bus. Eight passengers were killed, in addition to the bomber, and 14 were wounded. Among the dead were four Israeli soldiers and Noa Shlomo, 18, a niece of Israel's ambassador to the United Nations, Yehuda Lancry, police said.

The bombing might help Sharon convince Israeli public opinion of the need to prolong the operation.

Although the offensive is widely supported in Israel, there was criticism yesterday of the army's practice of sending reserve soldiers, who have had little recent training in urban warfare, into complex operations like the sweep in Jenin camp.

Also yesterday, Lebanese guerrillas fired more than a dozen rockets and mortars at the Israeli-annexed Golan Heights and northern Israel in one of the most extensive attacks since Israel withdrew from Lebanon nearly two years ago. Israeli warplanes fired missiles at suspected guerrilla positions.