Guards battled for four hours to subdue some 800 rioting inmates at a Chino, California prison in one of the state's largest such uprisings in years, an official said on Sunday, according to Reuters. The fighting at the California Institution for Men in Chino east of Los Angeles began at 9:24 a.m. 1424 GMT on Saturday and continued until 1:30 p.m. 1830 GMT, said Oscar Hidalgo, a spokesman for the California Department of Corrections and Rehabilitation. "They used everything from tear gas, batons, they used wooded and foam projectiles," Hildago said of the guards. "There were so many inmates involved at one time that they had to pull back and regroup." Officials brought in reinforcements from other prisons and local police, both to regain control of the prison and to assure that no one escaped from the area spanning 2,500 acres (1,012 hectares) during the fighting. One inmate suffered stab wounds and remains in serious condition; 27 other inmates were taken to area hospitals for medical treatment, Hidalgo said. Another 24 were treated for minor injuries at the prison and one guard suffered heat exhaustion.