U.S. forces found 20 to 30 bodies in a mass grave north of Baghdad, the U.S. military said on Monday.
The bodies were found on Sunday in the town of Muqdadiya, 55 miles north east of Baghdad, in the restive province of Diyala where al-Qaida Sunni Arab militants regrouped after being driven out of other areas.
"All the bodies were badly decomposed and appear to have been at the site nearly eight months," the military said in a statement.
"The coalition forces were unable to determine whether or not the bodies had been tortured at the time of death."
Mass graves are often found in Iraq, many a result of sectarian violence that killed tens of thousands of Iraqis, peaking in 2006 and the first half of 2007.
In the town of Mahmudiya, south of Baghdad the bodies of 40 people were found on Thursday.