A U.S. Army reservist has pleaded guilty to five charges of abusing detainees at Iraq's Abu Ghraib prison.

Staff Sergeant Ivan Frederick admitted to allegations of dereliction of duty, assault and indecency Wednesday, at his court martial in Baghdad.

He is expected to be sentenced Thursday.

Sergeant Frederick testified that he had abused detainees at Abu Ghraib for punishment or to assist with interrogations.

He also admitted to helping strip prisoners and forcing them in to humiliating positions -- photographs of which sparked international condemnation.

Later this week, two military police officers at the center of the scandal, Sergeant Javal Davis and Specialist Charles Graner, will also go on trial in Baghdad.

Two separate inquiries have blamed leadership failures up the chain of command for conditions allowing the abuse.

In all, eight U.S. military police officers or soldiers have been indicted in connection with the abuse at Abu Ghraib. Two defendants pleaded guilty in earlier courts martial.

Some information for this report provided by AFP and AP.