WASHINGTON, Jan 16: A former US Army prison guard Charles A. Graner Jr., who was sentenced to 10 years in military jail, has said he was following his superiors' orders when he tortured prisoners at Iraq's Abu Ghraib prison.

A 10-member military jury passed the sentence on Saturday afternoon, three hours after hearing Graner's statement in which he laid out an often harrowing tale of a prison where officers instructed guards to abuse and torture prisoners.

At one point, he showed the jury a copy of the US Army's rules of engagement which instructed guards to "shout, shove, show a weapon and shoot" for controlling unruly inmates.

Graner also said cellblock One-Alpha housed a number of "ghost detainees," prisoners held with no written records to hide them from the Red Cross. Graner portrayed Abu Ghraib as an over-crowded prison where abuses were widespread, the management inept, and guards inexperienced and over-worked.

"They would say ... give this prisoner 30 seconds to eat," Graner recalled. The 36-year army reservists said officers-- ranking from lieutenant to full colonel-- clearly ordered guards to soften the prisoners for interrogation by CIA and military intelligence officers.