The militant Islamic group, Hamas, has vowed to wage "total war" against Israel on all fronts. The declaration was issued in response to Israel's killing of four members of the organization. Meanwhile, Israeli police say a Palestinian gunman wounded 15 people on a Jerusalem street just hours after the Hamas declaration.

Hamas, the Islamic Resistance Movement, issued a leaflet in Gaza City, saying Israel had, in its words, "opened the door to all out war against the Zionist Army and (Jewish) settlers, by all means and all places."

The declaration followed the killing Tuesday of four Hamas fugitives in their hideout in the West Bank town of Nablus by Israeli commandos.

Israel said its soldiers also arrested nine suspected militants and uncovered, what the army called, a Palestinian laboratory for making explosives. Israeli forces later pulled out of the town.

The Israeli army said the four killed had been released by the Palestinian Authority at the start of the current round of fighting and had been involved in the planning of bomb attacks against Jews.

Hamas, which is committed to the destruction of Israel, had agreed last month to partially observe a truce called by Palestinian leader Yasser Arafat.

The organization said it would halt suicide bombings and mortar fire, but this undertaking has now been cancelled according to the latest proclamation.

In Nablus, more than two-thousand Hamas supporters rioted outside the Palestinian police headquarters and demanded the release of more than two dozen Hamas detainees.

Protesters stoned police, setting fires and burning three police cars before the Palestinian security forces responded with tear-gas, live fire, and stun grenades.

But in the end, the Palestinian Authority attempted to appease the mob and a brother of one of the four men killed was released on the orders of Mr. Arafat.

Meanwhile, members of Mr. Arafat's Fatah faction also announced that they too would no longer uphold any cease-fire with Israel and would resume attacks against Israelis.