BAGHDAD (AFP) - A US soldier at the heart of the prisoner abuse scandal at Iraq's Abu Ghraib prison pleaded guilty to a range of charges from making hooded inmates masturbate to punching them in the chest.
However, Staff Sergeant Ivan "Chip" Frederick did not admit guilt to all of the elements of the five charges against him during the first of a two-day court martial on a military base at Baghdad's international airport.
He offered a rare insight into what went on behind the bars of the detention centre where pictures of grinning US soldiers posing by a heap of naked Iraqi men taken earlier in the year sparked worldwide outrage.
The extent of the alleged abuse became even more apparent when one of the prisoners testified, describing being hit and humiliated to the point of wanting to die.
Referring to a photograph of a pyramid of seven inmates -- one of the most notorious images from the Abu Ghraib outrage -- Frederick, the highest-ranking soldier accused in the affair, said they were criminal suspects who had been hooded and their hands tied.
"We threw them in a pile," he told the trial judge.
"That's when Sergeant (Javal) Davis started jumping in the pile," he said referring to one of two other soldiers due to appear in court this week.
Frederick said Davis had been "sort of" laughing as he stomped on the prisoners' hands and feet, and admitted that he could have stopped the abuse. "But I didn't."
Instead, the military policeman joined in as the detainees were stripped and abused, punching one of them, he said.
"I stood him up and punched him in the chest. I was angry. They told me he was the ringleader. He hit a female soldier in the face with a rock," said Frederick.
The man slumped down and signalled for an inhaler so a medic was called, but the ordeal did not stop there. The naked prisoners were lined up against a wall still with bags over their heads.
"I told one of them to masturbate," Frederick said.
"I grabbed his arm by the elbow, put it on his genitals and moved it back and forth with an arm motion and he did it," he said.
He revealed that other soldiers embroiled in the scandal, including Private First Class Lynndie England and Corporal Charles Graner, were watching and taking pictures.
Frederick admitted that he thought his actions had been indecent and immoral.
When asked by Colonel James Pohl, the presiding judge, why he did it, the soldier responded: "Just to humiliate him ... it makes the army look bad."
In an emotional appearance, the prisoner who was allegedly hit by Frederick and forced to masturbate described scenes of terror and suffering at the jail.
"I was crying. I wanted to kill myself," he told the judge before putting his head down on the witness stand, unable to continue with his story for a minute or two.
The Iraqi, whose identity was not released for security reasons, then described how, after the abuse, the seven prisoners were taken to their cells, which were flooded with water, and told to sleep there, naked with bags on their heads.
There were no beds or blankets, said the prisoner, who had been accused of stealing a car and rioting.
"I felt humiliated but I had nothing to kill myself with," the witness said.
Asked by the prosecutor whether he still felt this way, he replied, "yes."
Frederick alleged that military intelligence and criminal interrogators set conditions for interrogation and that one Criminal Investigation Division official asked the military police who were guarding the prisoners to scare them.
He described how they put one prisoner on a box, attached wires to him so he thought he would be electrocuted if he fell, and took photographs.
Frederick admitted that he took pictures for his memories rather than to be used as an interrogation tool.
Davis and Graner are due to appear before a judge at Camp Victory later this week.