In return, some Islamic fundamentalists are calling for the assassination of Palestinian Authority leader Yasser Arafat.

The crackdown included placing Hamas spiritual leader Sheik Ahmed Yassin under house arrest on Thursday of last week, after his organization claimed responsibility for the bombing.

In addition, more than 100 Hamas activists have been rounded up by the Palestinian Authority over the past week.

Palestinian security officials are also reportedly searching for Hamas fugitive Mohammed Deif, who is suspected of planning the bombing.

Yassin's arrest came after Prime Minister Benjamin Netanyahu called Arafat following the attack, telling him he must wage an all-out war on terrorism if he wants Israel to begin the redeployment as scheduled.

Arafat, in turn, vowed to track down the masterminds of the bombings and "try them for deliberately harming the Palestinians' national interests."

The Israelis also have made an arrest.

Gur Hamal, a Jewish settler, turned himself into police on Monday. He is suspected of bludgeoning to death a 68-year-old Palestinian olive grower last week.

The schoolbus blast occurred near the Gush Katif junction shortly after 7 a.m. A suicide bomber driving a car packed with dozens of pounds of explosives attempted to ram the bus, but was blocked by an Israeli army jeep.

The car detonated next to the jeep, killing Sgt. Alexei Nikov. An IDF reservist on board suffered a broken hip and leg and ruptured spleen, and another soldier suffered broken legs.

None of the 34 children, between the ages of 6 and 8, was injured, except for a few minor scrapes. The bus was damaged, some of its windows blown out and the front dented and blackened.

Deif has been hiding in the Gaza Strip for some time and Israeli officials believe he may have planned the attack as a "welcome gift" for Arafat following his return after signing the Wye Memorandum.

Deif is considered by Israel to be Hamas fugitive No. 1 and was the assistant of Yehiya Ayyash, "The Engineer." Deif is wanted for the murder of soldier Sharon Edri and a number of terror attacks.

The suicide bomber is believed to be Mohammed Abdullah, of Khan Yunis, a member of Hamas' military wing.

Officials believe Abdullah waited for the convoy. As it turned at the Gush Katif junction, he drove from the opposite direction toward the busload of children. The bus was accompanied by two Israeli army jeeps at each end and a mini-bus.

Blocked by the jeep, Abdullah crashed into it and detonated his bomb. From the force of the blast, the jeep overturned in the air. It was blown some 300 feet and burst into flames.

Minutes after the blast, the Israeli Defense Force imposed a closure on the entire Gaza Strip

Until last week, Hamas had refrained from striking from Palestinian-controlled territory in order not to clash directly with the Palestinian Authority. But following the Wye agreement, it apparently realizes that a severe crackdown is on the way and it has nothing to lose.

"Everything that it can do, it will do. This is part of its plan to stop the peace," Israel's former deputy chief of general staff Matan Vilna'i said.

Since the recent slaying of the Awadallah brothers, Hamas' military wing has suffered from lack of clear leadership. Military sources insist that Hamas' intention to carry out attacks has not waned, but it is becoming increasingly clear that it is having difficulty mounting attacks inside the Green Line.

The military wing of Hamas also warned Sunday that a continuing crackdown on the movement may push some activists to turn their guns on the Palestinian police.

Until now, apparently in deference to Arafat's role as a symbol of Palestinian unity, Hamas had stopped short of issuing direct threats against him.

The warning, in a leaflet faxed to news agencies, lashes out against what it calls the Palestinian Authority's "continued repressive measures" against Hamas.

It accused Arafat of having "reached the point of treason" by moving against Hamas. It also called for an immediate end to the crackdown in order to spare Palestinians "the horrors…of civil war" and Arafat's camp the "fires of revenge."

In Lebanon, Hezbollah called Arafat a traitor and suggested he should be assassinated over the Wye Memorandum.

"Is there no Palestinian who can do what [Egyptian President Anwar Sadat's assassin] Khaled Islambouli did and say that Arafat's presence on the face of this earth is shameful to the Palestinians and the Moslems?" Hezbollah leader Sheik Hassan Nasrallah told the mass rally.