A fight at a Southern California prison has left three inmates with serious injuries.
State corrections officials say seven prisoners attacked an inmate Thursday morning at the Richard J. Donovan Correctional Facility in San Diego.
The inmates struck the man in the head with a cane and after trying to run away, authorities say he fought back with a homemade weapon.
Guards used pepper spray to break up the fight.
Three inmates with serious injuries were taken to the hospital. Authorities say they had head cuts and stab wounds to the stomach and the head. A fourth man was treated for injuries at the prison.
In February, a riot involving nearly 50 inmates injured 10. In that incident, several fights erupted simultaneously on the South Bay prison's yard for medium-custody prisoners.
Investigators were looking into any tension or history in Unit A that may have led to the riot.
Donovan Correctional Facility is a state prison located just north of the Otay Mesa Point of Entry and on the outskirts of the Otay Open Space Preserve.