Downtown LA is a scene of pandemonium and lawlessness

A shirtless man waving a Mexican flag stands atop a burning car in the heart of Los Angeles, as another man throws a traffic cone into the flames and some play drums and shout chants in opposition to immigration officials.

In the background, city hall can be glimpsed through a haze of thick black smoke. The downtown district of one of America's biggest cities was a scene of pandemonium and lawlessness as protests, which had previously been mainly peaceful, turned ugly.

Critics of Donald Trump said the president's extraordinary decision to deploy National Guard troops, defying the wishes of the state's governor, had inflamed tensions and stoked emotions. The 101 Freeway, the main highway cutting through the downtown area, was also closed down for much of the day as police and protesters faced off, with flash bang devices sending some people scattering.

Bottles and other projectiles were hurled towards police, who responded by using tear gas and rubber bullets. It was this chaos, his critics say, that Donald Trump wanted to provoke.

Trump's decision to call in 2,000 National Guard troops, several hundred of whom were on the streets of LA on Sunday, was taken without consultation with the California governor and LA mayor, and marked an extraordinary escalation by the president. The military arrived on Sunday morning and was ordered to guard federal buildings, after two days of protest against Immigration and Customs Enforcement (ICE) officers.

As part of Trump's closed border policy, ICE has been ordered to find, detain and deport as many illegal immigrants as possible, and it was these raids that stoked the first signs of protest on Friday into the weekend. By midday Sunday, the military was surrounded by protesters outside the Metropolitan Detention Centre in downtown LA.

It was here that many immigrants had been held before being shipped off to detention facilities. The walls and floors are covered in expletive-ridden graffiti, reading f*** ICE.

The Los Angeles police soon split the crowd and drove a wedge between the National Guard and the crowd. California Governor Gavin Newsom has called Donald Trump's acts those of a "dictator, not a president".

He's formally requested that the Trump administration withdraw the National Guard. The White House say the military will remain there until order is restored.

Five hundred marines are still on standby. Los Angeles Police Department police chief Jim McDonnell, asked whether the National Guard was needed, said: "This thing has gotten out of control." He said that although the LAPD would not initially have requested assistance from the National Guard, the disorder had caused him to reevaluate his assessment.

Several people were arrested. Sky News witnessed a young woman, who called herself Gabriella, riding her motorbike at speed towards a line of police officers.

Read more from Sky News:Analysis: Trump deploys federal force in LATrump claims CA officials 'can't do their jobs' One of the police officers used his arm to push her off the bike. She said she was protesting because her "people were being rounded up." Politicians on both sides of the aisle condemned the violence, but some vehemently disagreed about what actions led to the escalation..