Protests over hard-line immigration tactics have ignited across the United States after days of demonstrations in Los Angeles, as California prepared for a legal showdown over U.S. President Donald Trump's deployment of the military.

More than 1,000 people massed Wednesday in America's second-biggest city for a sixth day of protests, with the crowd peaceful as they marched through the streets.

A second night of curfew was in place as city leaders try to get a handle on the after-dark vandalism and looting that scarred a few city blocks in the 1,300 square kilometer metropolis.