Israeli forces were pulling out of a Gaza refugee camp early Friday, leaving destruction behind after a two-day sweep killed at least 15 people, most of them militants, part of a relentless offensive in Gaza.

Residents said Israeli tanks and troops were heading back toward the nearby Israeli border before daybreak. The Israeli military confirmed that the incursion was over, but Israeli forces would continue operating there and in other places in the coming days in its campaign against Gaza militants.

The Israeli offensive in Gaza began after Hamas-linked militants killed two soldiers and captured a third in a June 25 cross-border raid. Israeli ground forces have moved in and out of several sections of Gaza, targeting militants and weapons, while Israeli aircraft fire missiles and drop bombs.

Four Palestinians were killed after a house owned by Hamas activist Mohammed Harara, was struck by an Israeli tank shell. The army said it fired at two gunmen who were on the roof because they were preparing to launch an anti-tank weapon at their forces.

Gaza Hospital spokesman Dr. Jumah Sakah said the dead from the strike include Harara, along with his mother, Sabah, and his two brothers.

The house was across from the Karni cargo crossing between Israel and Gaza, where Israeli tanks and troops have been massing during a three-week offensive in Gaza, sometimes entering the territory.

About 119 Palestinians have been killed in the violence. Many of the victims were gunmen, but before the Mughazi incursion at least 16 were minors, the U.N. reported. Israeli forces have mostly attacked government compounds and open areas militants use to fire rockets toward Israel.

The offensive has continued even as Israel waged a new campaign in Lebanon against Hezbollah, which began July 12 after Hezbollah guerrillas crossed the border, killed three soldiers and captured two others.

In Nablus, some 4,000 Palestinians demonstrated against Israel's actions in Gaza, and chanted their support for Hezbollah and its leader, Sheik Hassan Nasrallah.

"Nasrallah, our beloved, we are with you until the end. From Gaza to Lebanon the Muslim nation will not be ignored."

After two days of battles in the Mughazi camp, Israeli forces left behind considerable destruction, leveling farmland, tearing up water pipes and knocking down electricity wires. Some people in the camp of 22,000 were trapped in their houses by embankments the Israelis built as tank emplacements, residents said.

Residents also said 15 Palestinians detained by Israeli forces for questioning were released before the troops pulled out.

On the second day of the raid, five Palestinians were killed, after nine died on Wednesday, including a mother and her daughter.

On Thursday the Israeli army dropped leaflets in Gaza City warning it will attack homes where Palestinians hide weapons for militants and pressed ahead with a deadly sweep through a refugee camp,

The Arabic leaflets dropped over Gaza City warned that "anyone who has, or is keeping an arsenal, ammunitions or weapons in their house must destroy them, or they will face dangerous consequences."

Military officials told The Associated Press the army is adopting a new policy of attacking homes in civilian areas where weapons, such as the homemade rockets routinely fired into Israel, are hidden. The officials spoke on condition of anonymity because they were not authorized to speak to the media.