Updated

U.S.-led coalition troops and Afghan militia killed 18 rebel fighters during a six-hour firefight in eastern Afghanistan, calling in airstrikes to help repel the attackers, the U.S. military said Tuesday.

Six Afghan militiamen were wounded in the fighting that began Saturday morning, the coalition said in a statement.

Coalition forces were patrolling 27 miles south of a base in Shkin in Gomal district of Paktika province when they made contact with as many as 25 fighters, the military said.

During an exchange of small-arms fire by ground forces, A-10 Thunderbolt airplanes and Apache helicopters were called in for airstrikes. One vehicle was destroyed, and the rebels retreated, the military said.

The clash was reported Monday by Afghan officials, but they gave conflicting accounts. Tuesday's statement was the first by the coalition on the incident.

The statement didn't specify if the attackers were former Taliban or Al Qaeda terrorists. Remnants of those forces have mounted increasing attacks in Afghanistan's border regions with Pakistan.