GAZA CITY ø Israel's military has withdrawn ground forces from, but renewed air attacks on Palestinian insurgency targets in the Gaza Strip.

Israeli AH-64A Apache attack helicopters fired missiles toward three targets in the Gaza Strip on early Sunday. Two of those targets were in Gaza City and the third was in the northern part of the strip.

Palestinian sources said the targets included a building used by the ruling Fatah movement in Gaza City. Another target was the Hamas-aligned weekly Al Resala. The sources said the helicopters broadcast warnings in Arabic to stay away from targeted areas.

Israeli military sources confirmed the attacks ø the fourth round of air strikes conducted over the weekend ø and said the buildings were being used for the planning of operations against Israeli civilian and military targets in the Gaza Strip. They did not elaborate.

Earlier, Palestinian Authority Chairman Yasser Arafat, who heads Fatah, urged Palestinians to maintain attacks against Israel. Arafat's speech on Saturday came to mark the 56th anniversary of the Arab-Israeli war in 1948, which resulted in the establishment of the Jewish state.

"Find what strength you have to terrorize your enemy and the enemy of God," Arafat, quoting the Koran, said.

Over the weekend, Israeli troops were withdrawn from the the southern Gaza town of Rafah. The troops had participated in the search for the remains of five Israeli soldiers killed in a Palestinian rocket-propelled grenade attack on an Israeli armored personnel carrier on May 12.

On May 14, two Israeli soldiers were killed and two others were injured during the search operation. An Israeli military statement said one of the soldiers was killed as he was helping an elderly Palestinian woman carry her baggage into a home in Rafah.

On Saturday, Israeli aircraft bombed what the military termed a weapons laboratory operated by Islamic Jihad in Rafah.

The Jihad facility was said to have produced mines and stored weapons smuggled from Egypt.

The Israel Air Force also attacked the Al Ansar association. Military sources said Al Ansar, funded by Iran, served as a Hizbullah front for the recruitment and operating of insurgents.

"The research center exists under the facade of being an academic body," a military source said, "but in reality is used by the Islamic Jihad for its regular operations, including sending messages and information relating to operations of the organization, as well as coordinating between different bodies both in and outside of the Gaza Strip."