Seventeen people have been injured as Los Angeles police attempted to take away more than two tonnes of illegal fireworks for a controlled explosion.

At least nine Los Angeles Police Department (LAPD) officers suffered minor injuries as they confiscated around 5,000 pounds (2,268kg) of pyrotechnics in the south of the city.

They were taken to hospital along with six civilians - three with serious injuries and three with suffered moderate injuries, according to the fire department.

"Our bomb squad officers were in the process of seizing over 5,000 pounds of illegal fireworks in the area of 27th Street and San Pedro," LAPD tweeted.

"Some of the fireworks were being stored in our bomb squad trailer as a precautionary measure.

"Unknown at this time what caused an explosion."

The department's chief, Michel Moore, said protocols had been followed but that "something happened in that containment vehicle that should not have happened".

Pallet-loads of fireworks had been put on a tractor-trailer for disposal but some of the devices exploded, demolishing the truck.

The blast also knocked a nearby car on its side, smashed the windows of several others and blew out windows in a nearby home.

The force said officers would remain in the area while evacuations and an investigation took place.

Arturo Cejas, 27, has been arrested for possession of the illegal fireworks, which police say were transported into state to be sold for Independence Day celebrations.

"Many people see them as harmless, as something that just simply goes 'bang' and that is celebratory and fun," said Chief Moore.

"Tonight is a clear demonstration of the true and clear and present danger that fireworks in this city pose."