An Iraqi army medic told a U.S. military hearing Sunday he was sick for weeks after finding the naked and burned body of a 14-year-old girl allegedly raped and murdered by American soldiers south of Baghdad.

The medic gave his testimony on the opening day of a hearing to determine whether five U.S. soldiers must stand trial in the March 12 rape-slaying of Abeer Qassim al-Janabi and the killing of her parents and sister.

CountryWatch: Iraq

It is among the worst in a series of cases of alleged abuse of Iraqis by American soldiers.

The medic, whose name was withheld for security reasons, told the hearing that he was the first responder to enter the house and found the girl sprawled naked in the house, her torso and head burned by flames. She had a single bullet wound under her left eye, he said.

He testified that he found Abeer's 5-year-old sister, Hadeel, in an adjacent room. She was shot in the head and the bullet had blown the back of her head out, he said. The children's parents — father Qassim and mother Fikhriya — had suffered similar deaths: the mother's abdomen and chest were riddled with bullets, he said.

After witnessing the scene, the medic said he was ill for weeks.

He also told the hearing that because there was not enough space in the Mahmoudiya hospital to store the bodies, they were kept in an air-conditioned ambulance overnight, and buried the following day.

Four soldiers — Sgt. Paul E. Cortez, Spc. James P. Barker, Pfc. Jesse V. Spielman, Pfc. Bryan L. Howard — have been accused of rape and murder — and could face the death penalty. A fifth, Sgt. Anthony W. Yribe, is accused of failing to report the attack but is not alleged to have been a direct participant.

A former private, Steven D. Green, was arrested in North Carolina in June on rape and murder charges. Green has pleaded not guilty in federal court and is being held without bond.

The proceeding that opened Sunday is referred to as an Article 32 hearing, and is the military equivalent of a grand jury session.

The medic was among three Iraqi witnesses to give testimony Sunday. Reporters were not allowed to hear the first two witnesses but were allowed back in the hearing room when the medic took the stand.

Military prosecutor Capt. William Fischbach showed him a series of bloody crime scene photographs to confirm if the bodies were as he found them when he entered the room.

However, the defense attorneys alleged that the bodies were staged for the pictures. They also questioned whether the victims were shot to death, suggesting they were already dead when the bullets were pumped into their bodies.

U.S. officials are concerned the case will strain relations with Iraq's new government if Iraqis perceive the soldiers receive lenient treatment. The case has already increased demands for changes in an agreement that exempts U.S. soldiers from prosecution in Iraqi courts.

U.S. officials have assured Iraqis that the case will be pursued vigorously and that the soldiers will be punished if convicted. Prime Minister Nouri al-Maliki has demanded an independent investigation into the case.

The hearing is expected to last several days, and parts will be held in secret.

U.S. soldiers' conduct has come under spotlight over a series of similar incidents.

Four soldiers from another regiment have been accused of killing three Iraqi detainees in Samarra three months ago. The Article 32 hearing in that case wrapped up Friday in Tikrit but no decision on a trial was announced.

In another case, the U.S. command said Saturday that Sgt. Milton Ortiz Jr. of the 2nd Battalion, 28th Infantry Regiment of the Pennsylvania National Guard, was reduced in rank to specialist after pleading guilty to conspiracy to obstruct justice by placing a rifle near a mortally wounded Iraqi in February and threatening and assaulting an Iraqi in March.

The charges resulted from the killing of an unarmed Iraqi near Ramadi by Spc. Nathan Lynn, who was cleared last month of manslaughter and conspiring to obstruct justice.

Also, the Marine Corps and Navy prosecutors are reviewing evidence to determine whether to recommend criminal charges against Marines accused of killing 24 Iraqi civilians in Haditha in November.