Three members of the arson and explosives unit of the Los Angeles County Sheriff's Department have been killed in a blast at the department's training facility.

It was not immediately clear what caused the blast at the Los Angeles County Sheriff’s Department’s Biscailuz Training Academy center. No one else was injured, officials said.

An explosion at a Los Angeles County Sheriff's Department training facility on Friday killed three deputies, the sheriff said. The explosion took place at the Biscailuz Center Academy Training in East Los Angeles,