LOS ANGELES, United States, July 19, 2025 (BSS/AFP) - Three people died Friday in an explosion at a police training facility in Los Angeles, in what one local official called an accident.

"Tragically, they were three sworn members who were fatally killed," Los Angeles County Sheriff Robert Luna said.

"No other department members were injured or transported to any hospitals."

Speaking to reporters hours after the incident, Luna stressed that authorities had yet to determine the cause of the blast, but that there was no threat to the community.

"Within the last 30 minutes, the LAPD bomb squad rendered the scene safe," the sheriff said. "We have to go back and investigate what happened from the very beginning. I don't have the facts at this point."

Homicide detectives and personnel from the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives were at the scene, along with a bomb disposal unit from the Los Angeles Police Department.

An elected city official from the area where the blast took place ruled out terrorism and called it "a tragic accident."

"Early on, there were people speculating that this was intentional by, you know, some terrorists, but it was not, is what I'm hearing. It was a tragic accident," Supervisor Kathryn Barger said.

The Los Angeles Times newspaper quoted unnamed sources as saying that the facility's bomb squad was moving explosives following a bomb alert when the blast took place.

Law enforcement personnel enforced a large security perimeter around the parking lot where the explosion occurred, an AFP photographer saw.

- 'Horrific incident' -

Sheriff Luna said it was the largest loss of life for his department since 1857 and that the three people killed had served the country for a total of 74 years. Their names have not yet been released.

US Attorney General Pam Bondi posted on X that there "appears to be a horrific incident that killed at least three at a law enforcement training facility" and that investigators were on-site "working to learn more."

Mayor Karen Bass said "arson investigators and members of the LAPD bomb squad are assisting" at the scene in the Biscailuz Training Center in the Monterey Park area.

"The thoughts of all Angelenos are with all of those impacted by this blast," she said on X.

California Governor Gavin Newsom's office said he had been briefed, and was "closely monitoring the situation."

Footage from local station KTLA, which helicoptered over the training center, showed a person in bomb disposal gear working around a truck believed to contain explosives, which law enforcement personnel had covered with a large tent.