TWO INMATES WERE  stabbed multiple times and others were injured during a riot yesterday in an outdoor recreation yard at Folsom maximum security prison near Sacramento in California.

Guards fired a warning shot and used pepper spray to break up the fight among about 150 inmates at the prison, which is about 20 miles east of the state capital. It houses about 3,000 inmates.

The condition of the two inmates who were stabbed was not immediately known, said Terry Thornton, a spokeswoman for the California Department of Corrections and Rehabilitation.

Several other inmates were taken to outside hospitals, while others were treated at the prison for minor injuries, she said. The number of injured inmates and their medical conditions was not immediately known, she said.

No guards or other staff members were hurt during the skirmish, which began about 10:30 a.m.

The fight involved inmates from several different racial groups, but it is not clear why it started, Thornton said.

“That, is, of course going to be investigated,” she said.

Thornton said she did not know how quickly the fight was contained. The prison halted most inmate movements while it was investigated.

The brawl was on the B-Facility main exercise yard at the prison, which opened in 1986. Officials say the riot was the worst at the facility for 15 years.

-Additional reporting by AP