LOS ANGELES - A nighttime curfew was declared in Los Angeles as local officials sought to get a handle on protests that Donald Trump claimed were an invasion by a "foreign enemy."
Looting and vandalism have scarred the heart of America's second biggest city as largely peaceful protests over immigration arrests turned ugly after dark.
"I have declared a local emergency and issued a curfew for downtown Los Angeles to stop the vandalism, to stop the looting," Mayor Karen Bass told reporters.
Around 2.5 square kilometres of the city will be off-limits between 8pm and 6am for everyone apart from residents, journalists and emergency services, she added.
Small-scale and largely peaceful protests -- marred by eye-catching acts of violence -- began Friday in Los Angeles as anger swelled over ramped-up arrests by immigration authorities.
At their largest, a few thousand people have taken to the streets, but smaller mobs have used the cover of darkness to set fires, daub graffiti and smash windows.
Overnight Monday, 23 businesses were looted, police said, adding that more than 500 people had been arrested over recent days.
Protests have also sprung up in cities around the country, including New York, Atlanta, Chicago and San Francisco.
Trump has ordered 4,000 National Guard to Los Angeles, along with 700 active-duty Marines, in what he has claimed is a necessary escalation to take back control -- despite the insistence of local law enforcement that they could handle matters.
A military spokeswoman said the soldiers were expected to be on the streets later Tuesday or some time on Wednesday.
Their mission will be to guard federal facilities and to accompany "federal officers in immigration enforcement operations in order to provide protection."