The violence erupted when inmates "protested the transfer of unruly detainees to another compound", the military said. "During the disturbance, the detainees chanted, threw rocks and set several of their tents on fire. The disturbance was brought under control with only minor injuries to four guards and 12 detainees."

Members of the Red Cross who were visiting detainees at the time said guards shot rubber bullets and at least 14 prisoners were injured.

"The detainees complained about their conditions at the camp where they are living in the desert in tents where it is hot in the day and too cold at night," Ms Sidani said. "Many of the detainees complained they were not aware of the reasons for their internment or its duration. The Americans consider them 'security detainees'. There is no clear trial or legal process. In this climate, it takes one incident to ignite things."

Another view:

Sadr follower Saheb al-Ameri, secretary general of the Shahidallah charitable organisation, said the unrest was provoked by the refusal of prison authorities to give medical treatment to a detainee who had fallen sick and who was a member of the Sadr movement.

Other inmates became violent and US soldiers then fired rubber bullets and beat some prisoners, wounding 70 to 100 of them, he said, adding that since the riot, inmates have had no water or electricity.

There was another riot at Camp Bucca on January 31 that "ended with US soldiers firing into a crowd and killing four detainees." The U.S. is now holding more than 10,000 prisoners in Iraq.