A men's state prison was on lockdown after a racially charged riot involving hundreds of inmates left dozens injured over the weekend, authorities said. The riot erupted Saturday morning at California Institution for Men in Chino following a fight between a Hispanic inmate and a black inmate in a recreation yard, said prison spokesman Lt. Mark Hargrove. Anywhere from 200 to 800 other inmates watching from surrounding dormitories followed suit and clashed along racial lines, he said. More than 50 inmates were treated at the prison or local hospitals for serious to minor injuries in the 90 minute brawl, officials said. The prison would be on lockdown until at least Tuesday.