US-led coalition forces killed 15 militants in an operation in eastern Afghanistan overnight, the US military said yesterday, but a provincial governor said at least 10 civilians were killed in the raid.

The issue of civilian casualties is sensitive in Afghanistan and has eroded public support for international troops in the country. It also has driven a wedge between President Hamid Karzai and his Western backers.

"There was a ground operation targeting a Taliban commander. A number of militants manoeuvred on the force with small arms fire," US military spokesman Colonel Greg Julian said.

Eleven militants were killed by small arms fire while four were killed by close air support, the US military said in a statement.

"In an area where there was no threat to civilians, precision air weapons, not bombs, were used," Julian said. But the governor of eastern Laghman province, where the incident took place, said initial reports showed that 10 civilians were killed during the US-led operation.

"We have sent a team to the area to investigate, but the preliminary reports show that 10 civilians were killed as well as three who might be Taliban," Provincial Governor Lutfullah Mashal said.