The group Human Rights Watch said in a report to be released Sunday that U.S. military commanders encouraged abusive interrogations of detainees in Iraq, even after the Abu Ghraib prison scandal called attention to the issue in 2004.
Between 2003 and 2005, prisoners were routinely physically mistreated, deprived of sleep and exposed to extreme temperatures as part of the interrogation process, the report said.
"Soldiers were told that the Geneva Conventions did not apply, and that interrogators could use abusive techniques to get detainees to talk," wrote John Sifton, a senior researcher at Human Rights Watch.
The organization said it based its conclusion on interviews with military personnel and sworn statements in declassified documents.
A Pentagon spokesman, Cmdr. Greg Hicks, said he wasn't aware of the report, but noted the military is reviewing its procedures regarding detainees following a Supreme Court ruling that the Geneva Conventions should apply in the conflict with al-Qaida.
The Bush administration had previously held that certain enemies, including terrorists, were illegal combatants and not protected by those rules.
The conventions prohibit "outrages upon personal dignity, in particular humiliating and degrading treatment."
Human Rights Watch focused much of its report on a detention facility called Camp Nama at Baghdad International Airport.
One soldier, whose name was withheld from the report, described a suspected insurgent being stripped naked, thrown in the mud, sprayed with water and then exposed to frigid temperatures in an attempt to soften him up for interrogators.
Commanders, the soldier said, seemed confident that their treatment of prisoners was legal.
He described computerized authorization forms that had to be filled out before subjecting detainees to strobe lights, loud music, extreme heat or cold, or intimidation by barking dogs.
The allegations of abuse at the camp were first reported in March by The New York Times.