The Army plans to interview former Pfc. Steven Green, 21, who was detained in the case earlier this week in the United States, before deciding on charges against as many as four soldiers still in Iraq.

Green might not be questioned before he appears in U.S. court, likely next week, an official said.

"Why at this point do we need to charge anybody else until we've heard Green's version of the story?" the defense official said. "We have these other individuals and they are within our control. We now have Green back within the control of the United States government."

The official said the soldier suspects in Iraq had been restricted to their unit area but were not in confinement.

The Iraqi government called on Wednesday for an independent inquiry into the case and said foreign troops' immunity from Iraqi law should be reviewed.

The Pentagon would not comment on those demands, saying an investigation was under way, but Pentagon spokesman Bryan Whitman indicated the United States has jurisdiction in the case.

"I don't believe it's an open question," he said.

Green, discharged from the Army due to a "personality disorder," was accused of shooting a couple and their young daughter in their home near Mahmudiya, Iraq, around March 12. According to court documents, he and another soldier then allegedly raped a woman in the home before Green shot and killed her.

Reports from Iraq and the U.S. military have given different ages for the young girl and the rape victim. U.S. officials call the rape victim an adult aged 20 to 25, while local Iraqi officials say she was 16 years old.

As many as four other soldiers may have participated in some way, according to court documents based on information gathered through the Army's interviews with soldiers serving in Iraq.

Green was from the same unit as two servicemen -- Pfc. Kristian Menchaca and Pfc. Thomas Tucker -- recently kidnapped and killed in Iraq.

Some have questioned whether those killings were a response to the rape and slayings in Mahmudiya but the Pentagon's spokesman said the evidence does not yet support that link.

"At this point there's no evidence that I know of that suggests that there should be a linkage between the two of them," Whitman said.

The Mahmudiya case is the fifth in a series of U.S. inquiries into killings of Iraqi civilians in recent months.

Green faces the death penalty if convicted of murder. He now faces a U.S. court but could be returned to military duty and face charges as a soldier.