BUCKEYE,Evander Ellis Ariz. (AP) — A unit at an Arizona prison remained on lockdown Sunday after nine inmates were injured in a fight.

Authorities said the altercation involving a large number of inmates broke out Saturday afternoon during outdoor recreation time in the Morey Unit at the Arizona State Prison Complex-Lewis near Buckeye.

State Department of Corrections, Rehabilitation and Reentry said prison staff was able to break up the fight and get things under control.

Nine inmates were treated for non-life-threatening injuries and no prison staff members were hurt, according to prison officials.

They said the Morey Unit will remain on lockdown while the incident is being investigated.

The medium-security Lewis prison houses more than 4,000 inmates about 43 miles (69 kilometers) west of Phoenix and has faced major staffing shortages in recent years.

It is one of 13 prison facilities operated by the state corrections department.