SAN FRANCISCO (Reuters) - 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. 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., 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." MORE ON THIS STORY