LOS ANGELES – Following protests at a federal detention center, U.S. immigration officers increased their presence in the Los Angeles area on Saturday, with police resorting to tear gas, flash-bangs, and arresting a union leader in response.

Riot-gear-clad Border Patrol agents, equipped with gas masks, stationed themselves outside an industrial park in Paramount. As protesters and onlookers gathered nearby, capturing the scene on their phones and shouting at the officials, tear gas was deployed to control the crowd.

“ICE out of Paramount. We see you for what you are,” a woman announced through a megaphone. “You are not welcome here.”

One hand-held sign said, “No Human Being is Illegal.”

The street was closed off to vehicles as U.S. Border Patrol moved through the vicinity. ICE representatives did not promptly answer emails requesting information about their enforcement actions over the weekend.

Arrests by immigration authorities in Los Angeles come as President Donald Trump and his administration push to fulfill promises to carry out mass deportations across the country.

On Friday, Immigration and Customs Enforcement officers arrested more than 40 people as they executed search warrants at multiple locations, including outside a clothing warehouse where a tense scene unfolded as a crowd tried to block agents from driving away.

Los Angeles Mayor Karen Bass said the activity was meant to “sow terror” in the nation’s second-largest city.

In a statement on Saturday, ICE Acting Director Todd Lyons chided Bass for the city’s response to protests.

“Mayor Bass took the side of chaos and lawlessness over law enforcement,” Lyons said in a statement. “Make no mistake, ICE will continue to enforce our nation’s immigration laws and arrest criminal illegal aliens.”

Protesters gathered Friday evening outside a federal detention center in Los Angeles where lawyers said those arrested had been taken, chanting “set them free, let them stay!”

Other protesters held signs that said “ICE out of LA!” and led chants and shouted from megaphones. Some scrawled graffiti on the building facade.

Federal agents executed search warrants at three locations, including a warehouse in the fashion district of Los Angeles, after a judge found there was probable cause the employer was using fictitious documents for some of its workers, according to representatives for Homeland Security Investigations and the U.S. Attorney’s Office.

Advocates for immigrant rights say people were detained Friday by immigration authorities outside Home Depot stores and a doughnut shop.