Sustained gunfire and volleys of artillery could be heard from the village of Bir Ayad, 15 km (9 miles) south of Bir Ghanam. Rebels at Bir Ghanam hold the high ground on the outskirts of the town, their closest position to the capital, Tripoli, about 80 km (48 miles) away.

Ahmed, a rebel fighter in Bir Ayad, said a convoy of about 15 vehicles from Gaddafi's forces tried to approach Bir Ghanam, but the rebels fired at it and the convoy retreated after a about an hour of shooting.

Rebels in the Western Mountains have made steady progress in recent weeks after repelling assaults by Gaddafi's forces. Their target is the town of Garyan, which controls the highway south from Tripoli.

But the rebels have been hampered by divisions, ill-discipline and supply problems.

Rebel leaders won recognition as the legitimate government of Libya from the United States and other world powers on Friday in a major boost to the insurgents' campaign to oust Gaddafi.