Four corrections officers were injured and five inmates were taken to the hospital after a riot broke out at the state prison on Arizona's southern border, the Cochise County Sheriff's Office said early Monday.
The office said in a Facebook post that the riot at the Arizona Department of Corrections prison in Douglas was reported at 7:55 p.m. Sunday and lasted about an hour.
There were fights between groups of prisoners in the medium-custody Mohave unit, which has 940 beds, according to local KGUN-TV. The station said inmates there are not locked in cells and have free access to the yard during the day.
Inmates appeared to be on the roof of a building throwing rocks at vehicles approaching the prison, according to the sheriff's office's Facebook post.
The sheriff's office said in a statement that a perimeter was established around the prison, and no escapes were reported. In addition to Douglas police, the Arizona Department of Public Safety and the U.S. Border Patrol responded as well.