Two teenage gunman opened fire on Monday at the Islamic Center of San Diego in California, killing three men outside the mosque, one of them a security guard, before the two suspects were found dead, apparently from self-inflicted gunshot wounds, police said. All of the children who were attending a day school that is part of the mosque complex - the largest in San Diego county - were accounted for and safe after the shooting, which erupted shortly before 12 noon PDT (1900 GMT), according to San Diego Police Chief Scott Wahl. Wahl said the FBI was called in to assist in the investigation of the incident, which the police chief said authorities were treating as a hate crime. Scores of law enforcement officers called to the Islamic Center encountered the bodies of three men shot dead outside the building, including a security guard who Wahl credited with likely having helped prevent further bloodshed. A short time later, police discovered the bodies of two teenage males, aged 17 and 19, in a vehicle in the middle of a street, dead from apparently self-inflicted gunshot wounds, the chief said at an afternoon news conference