Curfew imposed in parts of downtown Los Angeles after days of protests

A limited curfew has been imposed in downtown Los Angeles as the authorities in the United States city try to quell several days of protests over the arrest of dozens of immigrant workers.

Mayor Karen Bass announced the measure on Tuesday saying it would be operational from eight in the evening to six in the morning, and likely remain in place for a few days.

City officials said it was necessary to stop vandalism and theft by agitators looking to cause trouble in the largely peaceful demonstrations.

Police started arresting dozens of protesters after the emergency curfew came into effect in pockets of the city where the demonstrations have been concentrated.

The protests intensified on Monday when President Donald Trump, in an almost unprecedented move, deployed the National Guard to the city without the state’s request.

Hundreds of US marines also arrived in the area on Tuesday under orders from Trump, ratcheting up tensions in the country’s second largest city.

California's Democratic governor, Gavin Newsom, condemned the deployment of the military and warned that "democracy is under assault".

On Tuesday, a federal judge denied the state’s request for an immediate restraining order that would have temporarily blocked the use of troops to enforce laws in the state, including immigration enforcement.

Newsom had said the deployment would only heighten tensions and promote civil unrest.

Police in LA have also expressed frustration with the federal move, saying the LA Police Department has successfully handled large-scale protests in the past.

Demonstrations against Trump’s immigration crackdown have spread to other cities across the country