The United States Navy says it has begun an investigation into photographs that appear to show some of its personnel abusing Iraqi detainees.
The pictures have not yet been authenticated
Some of the photographs, which were posted on the internet, apparently showed US special forces sitting on hooded and handcuffed detainees.
Another showed a man with a gun pointed at his head.
A navy spokesman said photographing detainees was prohibited, except for purposes such as keeping records.
He said the investigation would determine the identities and motives of the troops involved.
The pictures were handed over to officials by an Associated Press news agency reporter who found them on a commercial photo-sharing website.
The photographs, posted by a woman who said her husband brought them home from Iraq, appear to show the aftermath of raids on civilian homes, the Associated Press reported.
Seven US military police reservists were charged in the Abu Ghraib prison scandal which emerged publicly in April in photos showing abuse of naked Iraqi inmates.