NATO confirmed on Friday that at least 12 civilians were killed during anti-Taliban operations in southern Afghanistan this week as investigations continued into claims that at least 60 were killed.
President Hamid Karzai has also appointed a commission to investigate deaths in a series of clashes in the southern province of Kandahar on Tuesday that NATO said were directed at Taliban insurgents.
Local officials said at least 60 people were killed in a bombing raid in Kandahar late on Tuesday.
Some said none of them was Taliban, but others said they might have included Taliban.
The NATO-led International Security Assistance Force said Wednesday 48 Taliban were killed in three skirmishes on Tuesday.
"We can confirm at least 12 deaths and we are working with the Afghan ministry of defence to conduct further investigations," ISAF spokesman Captain Andre Salloum in the southern city of Kandahar said on Friday.
"But ISAF in the RC (regional command) South region can credibly confirm 12 deaths," he said.
Salloum said the force deeply regretted any civilian 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."
The possibility that there were others would be part of an investigation that could come to a conclusion in about a week, he said.
The chief of Panjwayi district, Niaz Mohammad Sarhadi, said he had reports that about 60 locals were killed in aerial bombing that also destroyed a number of houses.
The deputy director of Kandahar provincial council, Bismellah Afghanmal, put the figure as high as 85.
President Karzai appointed a commission on Thursday to investigate claims of civilian deaths after the fighting in an area around Panjwayi where ISAF and Afghan troops conducted a major anti-Taliban operation in September.
ISAF said Operation Medusa had delivered Taliban fighters, who were entrenching themselves in the area, their biggest defeat since they were removed from government in late 2001.
Tuesday's clashes were against groups of Taliban who were re-infiltrating, it said.
A government-appointed commission found that 53 civilians were killed during Operation Medusa.
The United Nations mission in Afghanistan said late on Thursday it was concerned about the report of new civilian deaths in the same area.
"The United Nations has always made clear that the safety and welfare of civilians must always come first and any civilian casualties are unacceptable, without exception.
"It is clearly in the interests of everyone that the facts be established regarding these events and it is imperative that a thorough investigation is carried out," it said in a statement.
Canada's Prime Minister Stephen Harper also lamented the deaths of civilians.
"I don't think these incidents help anybody, not NATO forces, not the Taliban," said Harper on Thursday.
Taliban militants use civilian casualties in their propaganda against the roughly 40,000 foreign soldiers in Afghanistan, whom the militants say have invaded the country.
Karzai last week urged the NATO forces to take more care to avoid civilian casualties after up to 20 more people were reported killed in two bombing raids targeted at Taliban insurgents.