The first of at least 2,000 National Guard troops began arriving in Los Angeles on Sunday morning, ordered in by President Trump to deal with protests against workplace immigration raids after two days of unrest.
Any demonstration that got in the way of immigration officials would be considered a "form of rebellion," Mr. Trump said in his order, issued on Saturday.
The dispatch of troops was an extraordinary escalation that put Los Angeles squarely at the center of tensions over his administration's immigration crackdown. It was the first time since 1965 that a president had bypassed a state governor to activate that state's National Guard force.
Gov. Gavin Newsom of California called Mr. Trump's order "purposefully inflammatory." He said there was no shortage of law enforcement resources to deal with the protests, and that the federal government was sending the troops because it wanted "a spectacle."
Protests broke out in Los Angeles on Friday against a series of raids that appeared to be part of a new phase of the Trump administration's immigration crackdown, in which officials say they will focus increasingly on workplaces. Protesters continued demonstrating downtown and in nearby cities on Saturday as law enforcement officers made arrests and in some cases used less-than-lethal projectiles, tear gas and flash-bang grenades against the protesters.
More demonstrations are scheduled for Sunday afternoon. Here's what to know:
How have the protests developed?
The demonstrations began on Friday after camouflage-clad federal agents began combing the garment district in Los Angeles in search of people suspected of being undocumented immigrants. The raid, which spread alarm among workers in the city, sparked chaotic scenes between protesters, who chanted and threw eggs, and law enforcement officers, who fired pepper spray and nonlethal ammunition.
Demonstrations continued Saturday, both downtown and in the greater Los Angeles area, including the largely Latino and working-class city of Paramount, about 16 miles to the south. Demonstrations there were some of the most volatile in the region, with law enforcement officers using flash-bang grenades and firing less-than-lethal projectiles at protesters.
Bill Essayli, the Trump administration's top law enforcement official in Southern California, said more than 100 people were arrested on Friday, and at least 20 more were arrested on Saturday, mostly in Paramount.
The streets of Los Angeles were largely quiet Sunday morning as the first National Guard troops began to arrive downtown at the Metropolitan Detention Center, where the Los Angeles Police Department had detained a number of protesters on Saturday.
What is the National Guard?
The National Guard is the only branch of the military that can be deployed both by state governors and by the president. Governors almost always control deployment in their states.
The Guard operates similarly to the Army reserve force. Most of its members do not serve full-time. They generally hold civilian jobs and attend regular training sessions and are called into active service only when needed.
The National Guard is most often called upon during extreme weather events like hurricanes, floods, and wildfires. Troops have sometimes been used to quell civil disturbances at the state governor's request. One example was in 1992 when Gov. Pete Wilson of California asked President George H.W. Bush to deploy the Guard after riots erupted in Los Angeles over the acquittal of four white police officers in the beating of Rodney King, a Black man.
Before Mr. Trump's move, the last time a president activated a state's National Guard troops without being asked to do so by the state's governor was in 1965, according to Elizabeth Goitein, senior director of the Liberty and National Security Program at the Brennan Center for Justice, an independent law and policy organization. On that occasion, she said, President Lyndon B. Johnson used troops to protect civil rights demonstrators in Alabama.
What have officials said?
Trump administration officials have criticized the state's political leadership over their handling of the protests, while California's Democratic leaders blasted President Trump's order as unnecessary and an inappropriate use of power.
Karoline Leavitt, the White House press secretary, said in a statement on Saturday night that Mr. Trump was deploying the National Guard in response to "violent mobs" that she said had attacked federal law enforcement and immigration agents. The 2,000 troops would "address the lawlessness that has been allowed to fester," she said.
Stephen Miller, the White House deputy chief of staff, said on social media that the protests were an "insurrection."
State and local authorities in California and Los Angeles County have not indicated any need for federal assistance. The state attorney general, Rob Bonta, said on social media that local law enforcement "have the resources they need to meet the moment," and that Mr. Trump's order was "counterproductive."
Gov. Gavin Newsom called the president's order "purposefully inflammatory" and said that Mr. Trump had activated the National Guard only because his administration wanted "a spectacle."
Mayor Karen Bass of Los Angeles said the National Guard's presence would "not be helpful." She said the city was capable of handling protests, she said, adding that she had been in contact with White House officials and Thomas Homan, Mr. Trump's "border czar."