KANDAHAR, Afghanistan (AP) – The American-led coalition confirmed that a battle between American forces and Taliban militants in southern Afghanistan caused civilian casualties, killing at least one child, and said a joint Afghan-American investigation is under way.

New airstrikes in the same area on Thursday killed 10 Taliban fighters after the insurgents ambushed a patrol, Eizatullah Khan, the Sangin district chief, said Friday.

The governor of Helmand province has said 21 civilians were killed in airstrikes Tuesday in the Sangin area of Helmand province, though residents of the area said the civilian death toll was higher.

In a statement late Thursday, the coalition said it had treated 20 Afghan civilians wounded in the 16-hour battle, including a child who later died.

“There are confirmed reports of civilian casualties,” but it was unclear how many, the statement said. “A joint Afghan and coalition force inquiry is being conducted.”

General Dan McNeill, the top NATO commander in Afghanistan, told NPR News’ “Morning Edition” that “it does appear there were civilian casualties” but that it wasn’t clear what caused them. He said it was likely the Taliban militants had been firing on coalition forces from civilian homes.

American Special Forces “got into an ambush by a far superior force, and as they tried to work their way through this by shooting and moving, it became clear this was a pretty good size insurgent force who also could shoot and move pretty well,” General McNeill told NPR in an interview being aired Friday.

“And eventually the only way they were going (to) get out of it is – they got backed up to a river and between that and a piece of high ground – was to use airstrikes. It did not dissuade the insurgents.”

Haji Pir Mohammad, who lives in the village where the battle Tuesday took place, said Friday that 37 people were killed after aircraft bombed four civilian homes – including 12 members of a single family. Another villager, Mohammad Asif, said earlier this week that 38 civilians died in the airstrikes.

Helmand Governor Wafa has said that 21 civilians were killed.

“There are always people who will say that 40 or 60 people were killed, but the civilian toll appears to be around 20,” said Khan.

Mr. Wafa has said Taliban militants sought shelter in civilian homes during the fight between American Special forces and Taliban fighters, but Pir Mohammad said no fighters were in the village and American and Afghan troops had left an hour before it was bombed.

Death tolls in remote battle sites in Afghanistan are nearly impossible to verify. The battle in Sangin marked the third major incident resulting in civilian deaths in the last several months, sparking outrage among Afghans and a warning from President Hamid Karzai that civilian deaths can no longer be tolerated.

In March, American Marines Special Forces fired on civilians after a suicide attack in eastern Afghanistan, killing 19 civilians and wounding 50. Late last month airstrikes and fighting killed some 50 civilians in the western province of Herat, Afghan and U.N. officials say.