Militant fighters streaming from a village and a mosque attacked a pair of remote outposts near the Pakistan border, killing eight American soldiers and as many as seven Afghan forces in one of the fiercest attacks of the troubled war.
The Taliban claimed responsibility.
The raid began around dawn on Saturday morning and lasted several hours, said Jamaludin Badar, governor of Nuristan province.
Mr Badar said the two outposts were on a hill - one on top and one at the foot of the slope - flanked by the village on one side and the mosque on the other.
The US military statement said the Americans and Afghans repelled the attack by tribal fighters and "inflicted heavy enemy casualties."
"This was a complex attack in a difficult area," Colonel Randy George, the area commander, said in the US statement. "Both the US and Afghan soldiers fought bravely together."
Nuristan, bordering Pakistan, was where a militant raid on an outpost in July 2008 claimed the lives of nine American soldiers and led to allegations of negligence by their senior commanders. Army General David Petraeus last week ordered a new investigation into that firefight, in which some 200 militants armed with machine guns, rocket-propelled grenades and mortars pushed their way into the base.
Mr Badar said he had sought more security forces for Kamdesh, the district where Saturday's attack took place, and said Taliban fighters had fled to Nuristan and neighbouring Kunar after Pakistani forces drove many extremists from the the Swat Valley earlier this year.
"When there are few security forces, this is what happens," he said.
He also complained about a lack of co-ordination between international forces and Afghans.
A Taliban spokesman, Zabiullah Mujahid, claimed responsibility and said 35 Afghan police are in Taliban custody, including the district chief, and that a council would decide their fates. Badar said no Afghan police were missing.
The US statement said the attack would not change previously announced plans to leave the area.Reuse content