Three sheriff’s deputies were killed in an explosion on Friday morning at a law enforcement training center in Los Angeles, local and federal officials said.

At least three people have died in an explosion at a Los Angeles County Sheriff’s Department’s training facility on Friday morning, according to US Attorney General Pam Bondi.

A state official briefed on the incident, who spoke on condition of anonymity because he was not authorized to discuss the investigation, said preliminary information had suggested that the explosion...