When can a president deploy National Guard on US soil?
US President Donald Trump has called for 2,000 National Guard troops to be deployed to Los Angeles where protests against immigration raids have escalated.
His decision to summon the National Guard overruled the authority of California Governor Gavin Newsom, who called the move "purposefully inflammatory".
At least 118 immigrants were arrested in operations across the city over the past week, which led to tense scenes as crowds gathered outside businesses thought to be raided.
The LA County Sheriff's Department said crowds "became increasingly agitated, throwing objects and exhibiting violent behaviour", prompting police to use tear gas and stun grenades.
Governor Newsom, along with the LA mayor and a California congresswoman said in separate comments they believed local police could handle the protests. Twenty-nine people were arrested, according to local officials.
Can the president deploy the National Guard?
To quell the growing unrest, Trump issued a directive under a rarely used federal law that allows the president to federalise National Guard troops under certain circumstances.
The National Guard acts as a hybrid entity that serves both state and federal interests. Typically, a state's National Guard force is activated at the request of the governor.
In this case, Trump has circumvented that step by invoking a specific provision of the US Code of Armed Services titled 10 U.S.C. 12406, which lists three circumstances under which the president can federalise the National Guard.
If the US "is invaded or is in danger of invasion by a foreign nation"; "there is a rebellion or danger of a rebellion" against the government; or "the president is unable with the regular forces to execute the laws of the United States".
Trump said in his memorandum requesting the National Guard that the protests in Los Angeles "constitute a form of rebellion against the authority of the Government of the United States".
According to experts, this is the first time the National Guard has been activated without request of the state's governor since 1965.
In 1992, the National Guard was federalised in LA during riots after police officers were acquitted for the beating of black motorist Rodney King.
Then-President George HW Bush sent troops at the request of California's governor at the time, Pete Wilson.
In 2020, National Guard troops were deployed in some states in the wake of protests over the killing of George Floyd.
How have officials responded to Trump's order?
Senior figures in the Trump istration have backed the president's decision to mobilise the National Guard. Defence Secretary Pete Hegseth said on social media it was "COMMON SENSE", adding: "Violence & destruction against federal agents & federal facilities will NOT be tolerated."
Senator Markwayne Mullin, an Oklahoma Republican, told CNN: "Does it look like it's [the protests] under control? Absolutely not."
However, that has been rejected by several Californian officials who insist city police are equipped to deal with the unrest, and the military's involvement is unnecessary.
California congresswoman Nanette Barragán, a Democrat who represents the city of Paramount in LA's suburbs where the protests have taken place, told CNN: "We don't need the help."
The National Guard is "only going to make things worse," she said.
Her words echo that of Governor Newsom, who also spoke against National Guard troops being sent to his state.
"The federal government is taking over the California National Guard and deploying 2,000 soldiers in Los Angeles — not because there is a shortage of law enforcement, but because they want a spectacle," Newsom wrote on X.
LA Mayor Karen Bass told ABC7 the National Guard's deployment was unneeded.
What has ICE been doing in LA?
Immigration and Customs Enforcement (ICE) officers conducted raids in heavily Latino parts of LA on Friday, as part of Trump's crackdown on illegal immigration.
Forty-four people were arrested, said a spokesperson for Homeland Security Investigations, a branch of ICE.
The efforts are a part of the president's aim to enact the "biggest deportation operation" in US history.
Los Angeles, which has a high foreign-born population, has been a big target.
In early May, ICE announced it had arrested 239 undocumented migrants during a weeklong operation in the LA area, as overall arrests and deportations lagged behind Trump's expectations.
The following month, the White House increased its goal for ICE officials to make at least 3,000 arrests per day.
Authorities have expanded their search increasingly to include workplaces such as restaurants and retail shops. The LA raids that sparked the protests occurred at a wholesale clothing supplier and a Home Depot outlet.
"You're going to see more work site enforcement than you've ever seen in the history of this nation," Trump's border official Thomas Homan said.
The ambitious deportation campaign has included rounding up migrants on military planes and sending them to Guantanamo Bay, a US military detention facility accused of human rights abuses, before bringing them back to Louisiana.
Other migrants have been deported to a mega-prison in El Salvador, including at least one who was in the US legally. Some migrants have been sent to countries where they are not from.
Many of these actions have been met by legal challenges in court.
How has LA responded to the raids?
On Friday, several protesters clashed with federal agents outside of a clothing wholesaler. They threw objects at agents and attempted to block federal officials from carrying out their arrests. In response, agents in riot gear used flash bang grenades and pepper spray to subdue the crowd.
Outside a Home Depot store in Paramount, roughly 20 miles (32 km) south of downtown LA, tear gas and flash bangs were deployed against protesters.
In a social media post, ICE described the scene on Saturday, saying: "Our brave officers were vastly outnumbered - over 1,000 rioters surrounded and attacked a federal building."
Responding to the protests, the LA Police Department said it made 29 arrests, almost all for failure to disperse, which is a misdemeanour, according to the BBC's media partner CBS News.