A gunman sneaked onto the grounds of an Orthodox Jewish high school in the West Bank late Tuesday and killed three teen-agers, even as Israeli troops kept up daily raids into Palestinian towns.

The man shot and killed three Israeli students outside a high school in the settlement of Itamar, near the Palestinian city of Nablus, settlers and rescue service officials said. The attacker was shot and killed by the settlement's security chief.

Hezi Katoa, a rescue service worker, told Israel Radio that they found one student hit by a number of bullets in the chest, and then two more "lying behind the building with bullet wounds all over their bodies." All three were dead at the scene, he said.

Itamar is known as a settlement of Orthodox Jewish militants who believe the West Bank belongs to Jews, not Palestinians.

A few hours earlier, an Israeli motorist was killed and another wounded in a shooting attack, apparently by a Palestinian gunman, near the Jewish settlement of Ofra, said rescue services spokesman Yeruham Mandola.

The violence accompanied repeated Israeli incursions into Palestinian towns in the West Bank.

Late Tuesday, Israeli soldiers entered Beitunia, a suburb of the West Bank town of Ramallah, Palestinians said, and surrounded the house of a prominent Hamas leader. However, the leader, Hassan Yussuf, was not there. The Israeli military had no comment.

In another development, Israel launched the spy satellite Ofek-5, displaying advanced missile capabilities and restoring a military eye in the sky after its last spy satellite burned up in the atmosphere about a year ago.

Defense Ministry spokesman Yarden Vatikay confirmed it was sent into space from a seaside Israeli air force base. It was launched by a Shavit missile, related to the long-range Jericho ground-to-ground missile. Foreign experts have said the Jericho can carry a nuclear warhead; Israeli officials have not commented on that.

Israel's latest sweep in the West Bank came after a Palestinian blew himself up outside an ice cream parlor and cafe crowded with women and children in a Tel Aviv suburb Monday, killing Ruth Peled, 56, and her 18-month-old granddaughter, Sinai Kenaan.

The Al Aqsa Brigades, linked to Palestinian leader Yasser Arafat's Fatah movement, claimed responsibility and identified the bomber as Jihad Titi, 18, a cousin of a leading Al Aqsa militant Mahmoud Titi, who was killed in an Israeli tank attack last week.

On Tuesday, troops in armored personnel carriers and jeeps drove into Jenin and a nearby refugee camp at about 3 a.m. and left by midday. They arrested eight, including the local leader of the Islamic militant group Hamas, Rami Awad. Soldiers also searched an Islamic school, seizing computer disks, residents said.

There were heavy exchanges of fire with Palestinian gunmen.

In one incident, a 55-year-old Palestinian civilian, who had come out of his home to watch the fighting, was shot in the leg before dawn Tuesday, witnesses said. Israeli troops opened fire on an ambulance trying to retrieve the wounded man, witnesses said; the army said it was checking that report.

"We couldn't bring him to the hospital until 8 a.m. and by then he was already dead," said Ibrahim Dabaneh, director of emergency services in the city.

In one deserted neighborhood, the sound of a Palestinian gunman's Kalashnikov assault rifle echoed through the streets as Israeli armored vehicles fired heavy-caliber mounted machine guns toward the source of fire, and soldiers dashed across open ground toward the cover of an empty building.

In its stairwell, about a dozen soldiers lay down and went to sleep. They had been up all night, waiting for order to enter Jenin, whose refugee camp was the scene of some of the bloodiest battles in Israel's six-week West Bank offensive, Operation Defensive Shield, that ended earlier this month.

In Bethlehem to the south, Israeli forces combed the town for the third straight day Tuesday, blocking off the Church of the Nativity to prevent gunmen from taking refuge there. During Israel's earlier offensive, several dozen gunmen ran into the church ahead of Israeli forces, setting off a 39-day standoff that ended with the deportation of 13 of the militants.

On Tuesday, Israeli forces arrested four Palestinians and discovered a bomb and some weapons in the Dheisheh refugee camp next to Bethlehem, Palestinian security officials said.

The Israeli incursions have become an almost nightly occurrence. With the exception of the extended operation in Bethlehem, they usually last a few hours, resulting in the arrests of suspected militants.

Deputy Israeli Defense Minister Dalia Rabin-Pelossof admitted Tuesday that despite the arrest of thousands of suspected militants and the killing of dozens of wanted men, Operation Defensive Shield did not succeed in ending the militants' ability to stage attacks.

"We know now that there is nothing easier than to take a person bent on suicide and attach a bomb to him," she told Israel TV.

She denied that the Israeli military's frequent incursions into Palestinian territory are a precursor of another full-scale operation.

She said the defense establishment has a plan for a security fence between Israel and the West Bank and that "there should be a fence in the most sensitive parts [of the border] in a matter of weeks."

The border between Israel and the West Bank is largely open to infiltration, and to date Israel has avoided erecting physical obstacles for fear this might weaken its claim to at least some of the territory before a negotiated settlement. A fence would also leave many Jewish settlers on the other side from Israel.