At least three people have been killed after a "horrific incident" at a Los Angeles County Sheriff's Department training facility, officials have said.
A spokesperson for the department said there was an explosion at the Biscailuz Center Academy Training in east LA.
The incident was reported at around 7.30am local time (3.30pm UK time).
Aerial footage from local channel KABC-TV suggests the blast happened in a parking lot filled with sheriff patrol cars and box trucks.
A law enforcement official briefed on the matter, who spoke on the condition of anonymity, told the Associated Press an investigation is looking into whether the incident was a training accident.
Attorney general Pam Bondi wrote on X: "I just spoke to @USAttyEssayli about what appears to be a horrific incident that killed at least three at a law enforcement training facility in Los Angeles.
"Our federal agents are at the scene and we are working to learn more."
California congressman Jimmy Sanchez said the explosion had "claimed the lives of at least three deputies".
"My condolences to the families and everyone impacted by this loss," he said.
Several law enforcement sources told Sky's US partner network NBC News two devices were moved to the training centre overnight. They said one of the devices then exploded on Friday morning, killing three and injuring a sergeant.
According to the law enforcement sources, investigators are trying to determine why they were moved and whether they could have been made safe at the scene or handled more securely in a bomb-proof container.
The attorney general said in a follow-up post that agents from the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives are "on the ground to support".
The mayor of Los Angeles, Karen Bass, said the LAPD bomb squad has also responded to the scene.
"The thoughts of all Angelenos are with all of those impacted by this blast," she said.
California Governor Gavin Newsom has been briefed on the incident, his press office said in a post on X.
"The Governor's Office of Emergency Services is in contact with the Sheriff's Department and closely monitoring the situation, and has offered full state assistance," it added.
(c) Sky News 2025: 'Horrific incident' at sheriff training facility in LA - at least three people dead
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