Israeli troops tracked down the suspected ringleader of a deadly Palestinian shooting spree at an Israeli kibbutz, forcing him to strip to his underwear and surrender Thursday in the West Bank town of Tulkarem.

In a separate army action in the Gaza Strip, Israeli forces carried out an early morning raid in Gaza City — a congested place that ground troops rarely approach — and detained four Palestinian brothers suspected of making mortars.

The actions are part of a recent pattern in which the military sends tanks, armored personnel carriers and troops into Palestinian cities and towns on nighttime missions to seize militants.

In Tulkarem, soldiers surrounded the house where the kibbutz attack suspect, Mohammed Naefe, was hiding. He walked out with his hands up, stripped to his underwear to ensure he wasn't carrying explosives. An Israeli human rights group helped arrange the surrender of Naefe and two alleged accomplices.

Israel says Naefe planned the attack Sunday on Kibbutz Metzer, a communal farm. Five people were killed, including a mother and her two young sons. The suspected gunman, identified as Sirhan Sirhan, 19, remains at large.

The attack, carried out by the Al Aqsa Martyrs' Brigade, has embarrassed Yasser Arafat. The militia is linked to the Palestinian leader's Fatah movement, and the shooting came at a time when Fatah was trying to persuade the Islamic militant group Hamas to halt suicide bombings in Israel.

The kibbutz shooting led to a renewed debate about sending Arafat, who heads the Palestinian Authority established in 1994, into exile.

Prime Minister Ariel Sharon said Israeli security chiefs have advised him not to expel Arafat, as demanded by several hardline Cabinet members including Foreign Minister Benjamin Netanyahu, Sharon's rival for the Likud Party leadership in a primary election later this month. Polls suggest the winner of that primary has a good chance of becoming prime minister after general elections in January.

Sharon met soldiers Thursday in the West Bank not far from Tulkarem, and praised their efforts.

"To reach a diplomatic arrangement, we need to stop the terror," Sharon said. "I know it's a tough, complicated struggle, and I'm full of appreciation for your actions and I'm totally convinced that we will have successes."

In a related military operation in the West Bank city of Nablus, a 17-year-old Palestinian was killed when troops fired at about 50 youths throwing stones at armored vehicles.

The troops re-entered Nablus in a pre-dawn raid Wednesday, saying that orders for the kibbutz shooting came from Al Aqsa leaders in the city. Israeli forces have controlled Nablus for much of the past seven months. They said the latest incursion is open-ended.

In the Gaza City incursion, soldiers in about 30 armored vehicles and three helicopters converged on a house and seized four brothers of the Meqdad family on suspicion they have manufactured and distributed mortar shells used in attacks on Jewish settlements in Gaza. At least two brothers were members of the Palestinian security services, the Israeli military said.

Meqdads live just a few hundred yards from the home of leader of the Islamic militant group Hamas, Sheik Ahmed Yassin.

During the past two years, Israel has carried out frequent air strikes in Gaza City, the largest Palestinian city, but has generally avoided sending in ground troops. Thursday's raid — the army's deepest penetration into Gaza City — was seen as a warning to Yassin and other Hamas leaders that they are not out of reach of the Israeli security forces.

In the southern Gaza town of Rafah, Israeli gunfire near the Egyptian border killed a Palestinian man, Palestinian witnesses and the Rafah hospital said. The Israeli army said it was checking the report. Rafah is the scene of almost daily shooting involving the army and Palestinian militants.