The statement said the coalition had treated up to 20 villagers wounded during a 16-hour battle that also involved Afghan army troops in Sangin district of Helmand province on Tuesday.
One boy died of his wounds after being evacuated by coalition troops, it said.
|Grieving relatives were filmed by Al Jazeera
Women near one house that Al Jazeera visited said that a family was killed there, a mother, a father and eight children.
Afghan and coalition forces estimate a significant number of Taliban fighters, including a high-ranking commander, were killed in the battle.
The area is largely under Taliban control and Al Jazeera's cameraman was allowed to film there only after gaining permission from a senior Taliban commander.
At the funerals for some of the victims, one mullah vowed that he would keep fighting till his "last drop of blood" and to keep killing Americans.
Assadullah Wafa, the provincial governor, said he had no reports of Taliban casualties.
Western forces have been waging a widespread operation against Taliban fighters in Sangin in recent weeks.
Prior to the latest casualties, scores of civilians have been killed by Western forces in the past two weeks.
With anger already rising among Afghans over the toll, Sangin's residents have called on Hamid Karzai, the president, to come to see for himself how they have suffered.
Karzai has repeatedly urged foreign troops to avoid civilian casualties, to stop searching people's houses, and to co-ordinate attacks with his government.
Last week, Karzai said the patience of Afghans was running out.
On Tuesday, a US military commander apologised for the deaths of 19 civilians, killed by US troops in eastern Afghanistan in March.