REPRESA (CBS13) — Corrections officials say about 20 Inmates were involved in a riot at Folsom State Prison on Thursday morning.The incident happened just after 9 a.m. in one of the prison’s medium-security housing units while the inmates were in the middle of program activities.Correctional officers tried to break up the fight, but it took deploying chemical agents to stop the violence. After the fight, five inmates were taken to a nearby hospital to be treated for non-life-threatening injuries.No prison staff were hurt in the riot, officials say.