The Press-Enterprise newspaper says ( http://bit.ly/1bsrhON) the pair was last seen around midnight Saturday at the home of one of the girls.
Lt. Christian Dinco says it's unclear whether the girls might have run away or whether foul play was involved.
Twelve-year-old Raylynn Bolt is 5-foot-7 and 120 pounds with dirty blond hair and blue eyes. Fourteen-year-old Diana Tourdot is 5-foot-6 and 120 pounds with dark brown, shoulder-length hair and brown eyes.
Anyone with information on the girls' whereabouts is asked to call Riverside detectives.
Information from: The Press-Enterprise, http://www.pe.com