KABUL, Jan 13 (Reuters) - At least seven civilians were killed in a blast inside a mosque in eastern Afghanistan overnight shortly after a joint foreign forces-Afghan operation in the area killed four Taliban fighters, local officials said on Sunday.
The explosion occurred in the Sayed Abad district of Wardak province at about 2 a.m. local time (2130 GMT Saturday), said provincial governor spokesman Sahihullah Shahid.
"A convoy of Afghan and foreign troops came under fire from insurgents inside the mosque ... Seven villagers were killed by an explosion after the operation," Shahid told Reuters.
A spokesman for NATO's International Security Assistance Force (ISAF) said a joint special forces team conducted a night raid in the area, and was aware of reports of an explosion once the team had left. He added no civilians were killed in the joint operation.
Night raids and civilian casualties have been major sources of friction between the Afghan government and its Western backers, and have led to large protests and violence.
The Taliban and Wardak police said an ISAF air strike killed the civilians, but the coalition said no aircraft were used.
The ISAF spokesman said the joint force was fired at by Taliban fighters from a nearby building which is believed to be used as a mosque. The soldiers returned fire, killing four insurgents, he said.
"If that (civilian deaths) occurred, those civilians died somehow after the forces left the area," he said.
Taliban spokesman Zabihullah Mujahid, in a statement e-mailed to media, said "American forces" used two air strikes in an attack on the mosque. (Reporting By Hamid Shalizi and Dylan Welch; Editing by Jeremy Laurence)