A military judge on Saturday ordered the former commander of U.S. prisons in Iraq to testify at the trial of a soldier who says he was ordered to abuse detainees at Abu Ghraib (search).

Col. James Pohl, the judge, said Brig. Gen. Janis Karpinski's (search) testimony at the trial of Sgt. Javal Davis would be limited to conditions at Abu Ghraib and the interaction there between guards and military interrogators.

Davis told investigators that military intelligence personnel appeared to approve of the abuse. "We were told they had different rules," he told investigators, according to an Army report.

Karpinski has denied knowing about any mistreatment of prisoners until photographs were made public at the end of April showing hooded and naked prisoners being tormented by their U.S. captors. She was relieved of her command after abuses at the prison came to light.

In an interview with The Associated Press, Karpinski said a "conspiracy" among top U.S. commanders left her to blame for the abuses at Abu Ghraib. A report issued by an independent panel of nongovernment experts blamed Karpinski for leadership failures that "helped set the conditions at the prison which led to the abuses."

The hearing came as the Navy said it was investigating new photographs obtained by the AP that appear to show Navy SEALs (search) in Iraq sitting on hooded and handcuffed detainees. Other photos show what appear to be bloodied prisoners, one with a gun to his head.

Pretrial hearings for Davis and Spc. Sabrina Harman at Fort Hood Saturday were originally scheduled to begin next year in Baghdad.

Spc. Charles Graner Jr. (search), described as the ringleader and father of the child of Pfc. Lynndie England, is scheduled to appear in a military courtroom Monday. He is expected to seek dismissal of charges on grounds of undue command influence.

England, the woman shown in now-infamous photographs holding a naked Iraqi prisoner by a leash and smiling and smoking in front of nude Iraqis, also sought to call Karpinski as a witness, along with Vice President Dick Cheney and Defense Secretary Donald Rumsfeld. The judge in her case rejected those requests.

Charges against Davis, a native of Roselle, N.J., include conspiracy to maltreat detainees, assault, dereliction of duty and lying in official statements. He has acknowledged stepping on the fingers and toes of detainees, but denied hurting anyone and said he was ordered to "soften them up."

Harman, of Lorton, Va., is accused of photographing some of the abuse, participating in sexual humiliation of naked prisoners, writing "rapist" on the leg of a detainee who then was forced to pose naked with other prisoners, and placing wires in the hands of a detainee and telling him he would be electrocuted if he fell off a box.

She was photographed standing behind naked, hooded Iraqis stacked in a human pyramid and also shown next to a dead body packed in ice giving thumbs-up signs with Graner.

The three are among seven members of the Maryland-based 372nd Military Police Company charged with humiliating and assaulting prisoners at the Baghdad prison.

Graner, of Uniontown, Pa., is scheduled for trial beginning Jan. 7. Davis's trial will begin Feb. 1. Harman's trial date has not yet been determined, according to Fort Hood officials.