COALINGA, Calif. (AP) — A riot involving dozens of inmates at a Central California prison has ended with three injuries.

State corrections officials say about 41 inmates were involved in Thursday’s battle in a recreation yard at Pleasant Valley State Prison in Coalinga. The fighting began when three inmates attacked one prisoner and the brawling escalated.

When chemical agents failed to end the fighting, guards fired rifle warning shots to end it.

Three inmates had puncture wounds and are in fair condition at hospitals.

Two inmate-made weapons were found.

Authorities say no guards were injured.

Comments