The US marine corps has charged seven marines and a navy sailor with murder over the death of a disabled Iraqi man.
The US is looking into other cases of alleged abuse or killings in Iraq
All eight also faced kidnapping and conspiracy charges, a spokesman told reporters at the Californian camp where the defendants were being held.
They are accused of shooting a disabled man in Hamdaniya in April, and covering up the circumstances of his death.
It is one in a series of inquiries into the alleged abuse or killing of Iraqis by coalition forces.
Another Pentagon inquiry is looking into an alleged massacre at Haditha last November, in which 24 civilians are thought to have been killed.
The Hamdaniya investigation has been examining claims a man was deliberately killed on 26 April in the town in central Iraq.
The accused are alleged to have taken the 52-year-old victim from his house, shot him and then left a rifle and shovel by his body to make it appear as if he were an insurgent planting a roadside bomb.
Local Iraqis are said to have told marine leaders about the alleged shooting, which prompted an inquiry.
The accused were taken out of Iraq and held at Camp Pendleton in California.
A military spokesman said all were presumed innocent and it would be up to the authorities to decide if the men would face the death penalty in any future courts martial.
They have been identified as Sgt Lawrence Hutchins, Cpl Trent Thomas, Navy Hospital Corpsman 3rd Class Melson Bacos, Lance Cpl Tyler Jackson, Pfc John Jackson, Lance Cpl Jerry Shumate, Lance Cpl Robert Pennington and Cpl Marshall Magincalda.
"The marine corps takes allegations of wrongdoing by its members very seriously and is committed to thoroughly investigating such allegations," spokesman Col Stewart Navarre told reporters.
"The marine corps also prides itself on holding its members accountable for their actions."
Correspondents say the Hamdaniya and Haditha cases have generated a huge amount of unfavourable publicity for the marines and concern within the corps about the conduct of some in Iraq.
Separately, the US military in Iraq announced that murder charges had been filed against a fourth soldier following the shooting of three male Iraqi prisoners near Tikrit in northern Iraq on 9 May.
The announcement came after three soldiers were charged on Monday with premeditated murder in connection with the incident.
Another US inquiry has cleared marines of blame for the deaths of civilians in Ishaqi in March.
Earlier this month the US military announced that US-led troops in Iraq were to undergo 30 days of ethical training in the wake of the alleged massacre in Haditha.