It's the third claim of civilian casualties in Iraq from U.S. airstrikes in as many days.
In the latest incident, a U.S. helicopter opened fire on a group of men as they were planting roadside bombs in a Sunni stronghold north of Baghdad, then chased them into a nearby house, killing 11 Iraqis, including at least six civilians, the military said.
Police and witnesses, however, said 14 people were killed, including four women and eight children.
Maj. Peggy Kageleiry, a military spokeswoman, said an investigation was under way.
Associated Press writer Sinan Salaheddin reports the airstrikes have prompted complaints that too many ordinary Iraqis are losing their lives, particularly as the Americans increasingly rely on air power to attack militants.
To learn about the previous incidents, read Salaheddin's story here.
-- Jaime Holguin