An inmate was killed and several others were stabbed Sunday in a riot involving more than 160 inmates at a prison on California's central coast, authorities said.

The melee broke out around midday in the yard at the California Men's Colony near San Luis Obispo, the California Department of Corrections and Rehabilitation said.

The inmate who died was identified as Matthew Cook, 25, who was serving a 13-year sentence for burglary, the department said.

A total of nine wounded inmates were taken to an outside hospital for treatment.

Lt. Monica Ayon, a spokeswoman for the prison, tells the San Luis Obispo Tribune that visitors were escorted out when the riot broke out. The incident was contained to the yard, which was cleared after about an hour.

No guards were hurt.

Officials say they don't know what sparked the violence.

The California Men's Colony is a male-only state prison with about 3,800 minimum and medium security inmates, located 200 miles northwest of Los Angeles.