Gunmen fired at the house of Palestinian Prime Minister Ismail Haniyeh of Hamas early Monday and warring factions threw militants to their deaths from high-rise buildings, in a dangerous escalation of infighting in Gaza. There were no reports of casualties in the attack on Haniyeh's house in the Shati refugee camp next to Gaza City. His office wouldn't say whether he was inside when the house and surrounding area came under heavy fire for about 15 minutes from a nearby high-rise building. But his wife, children and grandchildren were in the house, his family said. It was the first time in a month of fighting between Hamas and the rival Fatah group that Haniyeh was an apparent target. Before daybreak Monday the sides reached an agreement to stop the clashes, and Fatah-linked security forces began pulling back from points of friction around the Gaza Strip. But several such cease-fires in recent weeks have been short-lived. Shooting could still be heard at several points around Gaza City as residents awoke Monday. The fighting took a grisly turn on Sunday, when Hamas militants kidnapped a member of the elite presidential guard of Palestinian Authority Chairman Mahmoud Abbas of Fatah, took him to the roof of a 15-story apartment building and threw him to his death. That set off skirmishes through the city, including gun battles and shelling. Fatah militants surrounded the house of a Hamas mosque preacher, fired rocket-propelled grenades at the four-story building and then entered, firing at the preacher, and taking him away. Later, his body was brought to a hospital. Hamas pledged revenge. And just before midnight, a Hamas activist was thrown off the 12th floor of a building and killed, security officials said. Four other Hamas men in the building were shot and wounded, bringing the day's toll to three dead and 36 wounded, medical officials said. A Hamas militant wounded Friday in southern Gaza infighting also died on Sunday. Fifty-five people have been killed in the latest outbreak of violence, most of them militants. A truce declared two weeks ago was meant to end the clashes, but last week the fighting resumed around the southern Gaza city of Rafah. Palestinian TV reported that Haniyeh called on gunmen to pull back from streets and rooftops to allow about 24,000 Gaza 12th grade high school students to start their final exams on Monday. The Education Ministry said Monday the tests would go ahead as planned.