'Catastrophic failure': Police blow themselves up with confiscated fireworks

The explosion was massive. Photo / Supplied

A US police operation to confiscate illegal fireworks went wrong earlier this in the worst possible way, as a "catastrophic failure" saw the illicit explosives blow up a police vehicle and injure 17 people.

Ten law enforcement officers were among the injured, including one who suffered a traumatic brain injury,

On Wednesday (US time), the Los Angeles Police Department seized at least two tonnes of illegal fireworks from a home near a primary school.

During the operation to move the fireworks, a cache of improvised explosive devices was found and placed in a "total containment vehicle" belonging to the bomb squad.

It couldn't contain what happened next.

The material inside exploded, destroying the vehicle and sending a blast wave into the neighbourhood.

"This was completely unexpected. They followed all the protocols in place. It was not really one of these explosions that was unplanned. This was planned," LAPD Lt Raul Jovel said at a press conference.

"This truck is rated for a lot more pounds than that - at least 15 pounds - so all protocols, training was followed," Jovel said. "We're not sure what happened. This vehicle came apart, literally."

Homes in the neighbourhood were damaged and the blast could be heard blocks away.

LAPD Chief Michel Moore said there was a "total catastrophic failure of that containment vehicle".

Residents described the blast as sound like a "really hard earthquake" and said "everybody was screaming, going crazy".

The police had been working to evacuate locals after they discovered the illegal cache, but had only evacuated two homes before the explosion.