Police in Los Angeles have clashed with demonstrators following riots against US President Donald Trump's immigration crackdown.

Trump has deployed 2,000 California National Guard troops to Los Angeles on a second day of violent clashes between hundreds of protesters and federal immigration authorities in riot gear, overriding objections from Governor Gavin Newsom.

The White House announced that Trump would deploy the Guard to "address the lawlessness that has been allowed to fester".

The riots were sparked following the arrests of more than a dozen people, accused of impeding immigration agents.

Los Angeles rioters clash with the National Guard after demonstrating against Donald Trump's immigration crackdown

A protester holds up a Mexican flag as burning Waymo cars line the street in Los Angeles, California

Footage from the riots shows police unleashing tear gas, flash-bang explosives and pepper balls while protesters hurled rocks and cement at Border Patrol vehicles.

Protesters have also been seen setting off fireworks and breaking up cinder blocks to throw at Border Patrol vans.

As officers departed, agents lobbed flash-bang grenades at groups of people who chased alongside the slow-moving convoy. Some protesters had thrown eggs and other objects at the vehicles.

Some police carried riot shields and others held rifles, as well as shotguns that appeared to be loaded with less-than-lethal ammunition.

Protesters clashed with Los Angeles police as they demonstrated against Trump's immigration laws

Protesters descended on an LA highway, holding signs such as "immigrants make America great" and "protect our community".

Police were seen restraining some individuals who confronted the officers.

Taking to social media, Mayor Karen Bass of Los Angeles expressed deep anger over the raids: "As Mayor of a proud city of immigrants, who contribute to our city in so many ways, I am deeply angered by what has taken place.

"These tactics sow terror in our communities and disrupt basic principles of safety in our city.

"My Office is in close coordination with immigrant rights community organisations. We will not stand for this."

A cloud of tear gas surrounds protesters

Doubling down on his decision to send in the troops, Donald Trump said he will "not let this country be torn apart", citing "law and order".

He fumed: "Well, we're going to have troops everywhere. We're not going to let this happen to our country. We're not going to let our country be torn apart like it was under Biden.

"And if we see danger to our country and to our citizens, and we'll be very, very strong in terms of law and order, it's about law and order.

"Nobody's going to spit on our police officers. Nobody's going to spit on our military."