Afghan local officials said at least 60 people were killed when
Nato troops staged a bombing raid against Taliban positions in the southern province of Kandahar on Tuesday.
A Nato spokesman said on Friday: "We confirm at least 12 deaths and we are working with the Afghan ministry of defence to conduct further investigations."
Captain Andre Salloum, a spokesman for the International Security Assistance Force, said that ISAF had killed 48 Taliban fighters in three skirmishes on Tuesday, adding that the force deeply regretted any civilians deaths in its operations.
The 12 were identified by troops on the ground after one incident, he said. "As soon as the battle ended, the troops on the ground were able to identify 12 civilians."
"We confirm at least 12 deaths and we are working with the Afghan ministry of defence to conduct further investigations"
Captain Andre Salloum, Nato spokesman
The possibility that there were others would be part of an investigation that could come to a conclusion in about a week, he said.
After visiting the wounded in hospital, Naik Mohammad, a tribal elder, said that 60 civilians had died in the incident.
Villagers also put the death toll at 60 dead while a member of the Kandahar provincial assembly said that 80 had been killed.
Witnesses said that 25 homes had been destroyed in nearly five hours of bombing.
If confirmed, the bombings will have caused the highest number of civilian deaths by multi-national forces since the US-led invasion of Afghanistan after the September 11, 2001 attacks.