At least three police officers were killed in an explosion at a County Sheriff’s Department training facility in East Los Angeles, officials say.

The explosion occurred at the Biscailuz Center Academy Training on Friday morning at around 07:30 local time (15:30 BST), according to first responders.

Confirming the deaths in a post on X, US Attorney General Pam Bondi called it a “horrific incident” and said that federal agents had been deployed on the scene and were “working to learn more”.

It was unclear what caused the explosion or if there were any more victims.

The explosion occurred in a parking lot of the Special Enforcement Bureau at the facility, the Los Angeles Sheriff’s Department (LASD) told BBC’s US partner CBS News.

California Governor Gavin Newsom has been briefed about the explosion and he is “closely monitoring the situation”, his office said in a statement on X.

Newsom’s office added that state assistance has also been offered to help respond to the incident.

The Department of Homeland Security is helping with the investigations, as are officers from the Bureau of Alcohol, Tobacco, Firearms and Explosives and members of the Los Angeles Police Department.

Kathryn Barger, Chief of the Los Angeles County Board of Supervisors, wrote in a statement that she is “closely tracking the situation as we learn more about what occurred and the condition of those affected”.

“My heart is heavy, and my thoughts are with the brave men and women of the Sheriff’s Department during this difficult time,” she said.