The Arizona state prison near Yuma is under lockdown after authorities were able to contain a riot involving hundreds of inmates Thursday night.
Inmates reportedly attacked prison personnel around 6:45 p.m local time at the medium-custody Cheyenne Unit of the complex.
Officials say around 600 inmates were involved in the disturbance, which included throwing rocks, setting fire to mattresses and other property in the yard and breaking into the prison health unit.
ADC response and tactical teams from Yuma, Lewis, and Tucson complexes brought the incident under control around 9 pm., according to a statement from corrections officials.
All prison staff are safe and accounted for.
The inmates involved are being contained in a fenced recreation yard as ADC investigates.
Additional criminal charges are pending for any inmates involved in violent activity.