Authorities say part of a southern Arizona prison is on lockdown following an hour-long disturbance in which 15 inmates and four corrections officers were injured.
Corrections Department spokesman Andrew Wilder says inmate movement is restricted and visitation canceled at the Douglas prison complex's 950-inmate medium-security Mohave Unit while authorities investigate.
Wilder says the disturbance started when groups of Hispanic and white groups began fighting in the unit's yard and that some inmates got on a building roof before the disturbance was quelled.
Wilder says circumstances remain under investigation.
He says one inmate was airlifted to a hospital for treatment of serious head injuries and that 14 other injured inmates were taken to hospitals for evaluation and treatment.
He says the four officers' injuries were minor and treated at the prison.