About 120 inmates were involved this afternoon in a riot at Salinas Valley State Prison, a Level 4 maximum security facility in Soledad.

Terry Thornton, spokeswoman for the California Department of Corrections and Rehabilitation, said the incident began about 3:15 p.m. In an exercise yard at the facility. Correctional officers used chemical agents, pepper spray and less lethal munitions in an effort to quell the disturbance. They later resorted to firing rifles. No inmates were wounded, Thornton said.

"The information I have at this time is very sketchy," Thornton said. "All I can confirm is that prison personnel quelled the incident, and all of the inmates have been controlled and returned to their housing."

Thornton said she had no information about how long the riot lasted, but said the last inmate was handcuffed and returned to his cell at about 4:45 p.m. The cause of the incident has not yet been determined.

"My first report of inmate injury is that four were hurt," she said. "Two suffered multiple head injuries, two others were stabbed."

Information on the extent of the injuries is not yet available, Thornton said. No prison employees were injured.

"Typically, after an incident of this size, that type of information takes a while to process and sort out."