Jerusalem ? A top Palestinian security official who is related to Yasser Arafat escaped assassination late Thursday after a rocket-propelled grenade was fired at his office, officials said. The explosive missed and hit a prison, wounding 10 inmates.

Speculation on the attempt against Maj. Gen. Moussa Arafat focused on fellow Palestinians because residents in the Gaza area said there were no Israeli army soldiers in the vicinity. An Israeli military source called the incident an internal Palestinian matter, without elaborating.

In a statement, Palestinian security said several of the injured prisoners had serious wounds. Among the inmates are suspected collaborators with Israel and criminals. Arafat’s office is in a compound that includes the central prison and security offices. Arafat, a cousin of the Palestinian leader, was not in his office at the time.

The attack came as Israeli soldiers, police and volunteers fanned out to try to find a missing soldier. Police expressed concern that he might have been kidnapped and killed by Palestinian militants, despite a cease-fire.

Oleg Shaichat, 20, was in uniform and armed when last seen Monday by a fellow hitchhiker traveling in a car near the biblical village of Cana on his way home to a nearby Jewish satellite of Nazareth, Israel’s largest Arab town.

The soldier’s disappearance followed the July 11 abduction of an Israeli taxi driver by militants. He was freed in a raid by Israeli commandos in the West Bank, and officials said afterward the captors apparently operated independently of Palestinian militant groups.

The main militant groups called a temporary truce June 29, but Israel and the Palestinian Authority are struggling to make progress on the stalled “road map” peace plan, a U.S.-backed blueprint for ending violence and establishing a Palestinian state by 2005.