At least 11 Palestinians are reported dead and some 100 wounded in an Israeli incursion into the Jabalya refugee camp in the Gaza Strip. The raid came just hours after a suicide bombing in Haifa Wednesday that killed 15 passengers on a city bus and wounded scores more.

Palestinian witnesses and medics said most of the deaths resulted when a tank shell hit, as people were trying to remove furniture from a wood shop set ablaze during fighting between Palestinian militants and Israeli troops.

But Israeli officials say the majority of the casualties resulted from an explosive device that went off inside the building, and that it was after that blast that the tank fired at a man preparing to shoot an anti-tank grenade.

Palestinian Cabinet Minister Saeb Erekat accused the Israelis of what he called an act of revenge, and he urged the quartet of Middle East peace negotiators to intervene to stop the violence.

The Israeli military described the raid as part of its ongoing war against terror. Officials said a senior member of the militant Islamic group Hamas had been arrested in the raid, and a large cache of weapons and explosives was seized.

Hamas vowed revenge for Thursday's Gaza raid.

Witnesses in the camp said the Israeli incursion began shortly after midnight, as helicopter gunships fired rockets into the area. That was followed by a force of some 50 tanks and bulldozers, which began demolishing homes of suspected Palestinian militants.

The raid came after Prime Minister Ariel Sharon's new security Cabinet met late Wednesday night to discuss the Haifa suicide bombing. The officials decided to impose a full closure on the West Bank and Gaza, and step up Israeli military operations.

Senior Palestinian leaders condemned the Haifa bombing, and Information Minister Yasser Abed Rabbo said such attacks only serve to distract attention from the many Palestinian civilians killed in Israeli military operations.