Arizona State Prison Complex in Tucson State  has remained under serious police watch after 400 prisoners engaged in a fight which left at least 19 of them injured,

The staff quickly stopped the fight that broke out Sunday morning at a minimum-security unit, State Department of Corrections spokesman Bill Lamoreaux says according to ABC news.

Lamoreaux says two staffers suffered minor injuries and 17 inmates were taken to area hospitals with injuries. The extent of the inmates’ injuries wasn’t immediately available.

The prison is investigating the cause of the fight, which broke out in the Whetstone Unit. Nearly 1,250 prisoners are housed in that unit, which is one of eight at the prison.

Prison officials cancelled visitations for the day to the entire prison after the fight.

By UP