Three US Marine officers have been censured over the alleged massacre of Iraqi civilians in the town of Haditha in 2005.
Maj. Gen. Richard Huck, Col. Stephen Davis and Col. Robert Sokoloski all received letters of censure for their responses to the killings in Haditha , the Marines said in a statement.
It was not immediately clear what affect the censures would have but administrative sanctions can mean that officers are unlikely to be promoted.
The Haditha killings followed a number of abuses by US forces in Iraqi towns and at Abu Ghraib prison outside baghdad which sparked outrage in Iraq and damaged the image of the US military as it waged war in Iraq.
Eight Marines were charged in the Haditha case. Procedures are under way against the alleged ringleader, charges against three men were dismissed and the other four have still to be dealt with.
Lt. Gen James Mattis, a senior Marine general looking into the officers' conduct, concluded they did not intend to cover up the case or break military laws.
"He did determine that their actions, or inactions, demonstrated lack of due diligence on the part of senior commanders and staff," the statement said.
Gen. James Conway, the commandant of the Marine Corps, said sanctions were necessary despite the officers' long years of service.
"While these three officers have served their country and Corps exceedingly well for decades, their actions, inactions and decisions in the aftermath of the Haditha incident did not meet the high standards we expect of Marine senior officer leadership," Conway said.