Eight troops being investigated in the death of an Iraqi civilian in April are being held in a military jail and four others have been restricted to their base, according to a U.S. Marine spokesman last Friday.

Lt. Lawton King said the eight were placed in "pretrial confinement" and four others were on "pretrial base restriction" at Camp Pendleton, California.

No charges have been filed, he said.

"The individuals were placed in pretrial confinement because of the commander's evaluation of the ongoing investigation," King said. "All of the individuals in pretrial confinement have been afforded the opportunity of a magistrate's hearing."

A source familiar with the investigation said Thursday that charges were likely going to be filed against "somewhere around seven Marines" in the case. The source spoke on condition of anonymity because charges have not been filed.

The Associated Press, quoting the defense attorney of one of the Marines, said the prosecutors plan to file murder, kidnapping and conspiracy charges against seven Marines and a sailor.

The Marines are suspected of killing an Iraqi civilian near Hamandiya, west of Baghdad, on April 26, according to a statement released last week.

The Iraqi civilian reportedly was dragged from his home and shot. Both the Los Angeles Times and NBC News said troops may have planted an AK-47 and shovel near the body to make it appear the man was an insurgent burying a roadside bomb.

Neither media outlet suggested a possible motive for the killing.

Maj. Gen. Richard C. Zilmer, commander of U.S. troops in western Iraq, asked for a probe by the Naval Criminal Investigative Service after Iraqis took the allegation to Marine commanders at a May 1 meeting.