Gunmen tried to storm a building of the American University of Beirut's Agriculture School east of the capital, but police returned their gunfire and forced them to retreat, a university official security sources said Monday.

Sources said five young men with automatic guns opened fire on 15 Lebanese policemen guarding the compound in the village of Hawsh Snaid near Baalbeck, 52 miles east of Beirut, late Sunday.The police returned fire and forced the gunmen to retreat, the sources said. The attackers, on an apparent sabotage mission, intended to storm the building, sources said.

There was no information on the political affiliation of the attackers, but analysts speculated the gunmen might be linked to Hezbollah, a pro-Iranian militia group that maintains large bases in the Syrian-patrolled eastern Lebanon. Hezbollah is believed responsible for the kidnapping of 12 Western nationals, including six U.S. citizens.

No one was hurt during the gunbattle, the sources said.