U.S. forces killed three Iraqi police officers Monday in a case of friendly fire during a raid near Ramadi, the military said.
The incident occurred during an operation targeting alleged al-Qaida in Iraq members northeast of Ramadi, which lies 115 kilometers (70 miles) west of Baghdad.
The U.S. military issued a statement Monday saying its troops "coordinated their operation and no Iraqi police were known to be in the area."
U.S. troops came under small arms fire from armed men they believed to be insurgents, and returned fire, the military said. The men were later identified as Iraqi police officers. Another policeman was wounded, the statement said.
The incident was under investigation, it said.
Seven suspected insurgents were also detained, it added.