A man on a motorcycle waves a Mexican flag as smoke rises from a burning car on Atlantic Boulevard during a standoff by protesters and law enforcement following multiple detentions by Immigration and Customs Enforcement in the Los Angeles County city of Paramount, California, on Saturday. Barbara Davidson/Reuters

Protests have gripped Los Angeles this weekend, sparked in response to immigration raids carried out on Friday.

Here’s what to know about the demonstrations:

Why did they start? Protests in and around Los Angeles erupted on Friday after at least 44 people were arrested by federal immigration agents earlier in the day. The arrests come amid Trump’s crackdown on immigration, which has involved waves of raids and deportations across the country. Late into Saturday, some protesters gathered near an immigration holding center in Alameda.

What happened on Saturday? Law enforcement used tear gas and flash bangs in an effort to disperse the crowd in Paramount, California, and some protesters were detained. But the situation escalated when President Donald Trump said he was deploying 2,000 members of the National Guard to control protesters in the evening. Trump claimed local officials had failed to deal with the unrest, and the federal government would “solve the problem, RIOTS & LOOTERS, the way it should be solved!!!”

How are people responding to the National Guard? California Gov. Gavin Newsom called the deployment of troops “purposefully inflammatory” and said it would only escalate tensions. The mayor of Los Angeles, Karen Bass, said there was no evidence of the National Guard on the ground, despite Trump praising their efforts. And the League of United Latin American Citizens also condemned Trump’s order, saying that the move “marks a deeply troubling escalation in the administration’s approach to immigration and civilian reaction to the use of military-style tactics.”

The latest from the ground: Small groups of protesters continued to gather and disrupt traffic near the Metropolitan Detention Center in Alameda late Saturday, despite repeated warnings from police to disperse. At midnight, the LAPD announced several people who re-entered areas of “unlawful assembly” have been detained and some will be “arrested and booked.” It is unclear how many people were detained.

The Los Angeles Sheriff’s Department told CNN some remaining protesters threw fireworks at law enforcement, while officers formed a skirmish line to push people away from the area.