The riot, which involved 60 inmates, began at 11:17 a.m. Wednesday in the prison's yard, the Los Angeles Times reported.
Officers fired six rounds to try to stop the violence, officials said. One inmate was shot and taken to a hospital.
Twelve inmates were taken to hospitals with stab and slash wounds from weapons made by inmates, as well as head injuries, officials said.
A number of other inmates were injured and treated at the hospital, said Terry Thornton, a spokeswoman for the California Department of Corrections and Rehabilitation. There were no reports of officers or prison staff being injured in the riot.
Officers recovered four weapons made by inmates, authorities said.
A deadly force investigation team from the corrections department is investigating the cause of the riot, officials said. A deadly force review board will also look into the handling of the riot.
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