Dozens of protesters gathered Friday evening outside a federal detention center in Los Angeles after federal immigration authorities arrested at 44 people.

Law enforcement threw flash bangs to try to disperse the crowd that had gathered outside a the detention center where they believed those arrested had been taken.

Demonstrators chanted “set them free, let them stay!” while other held signs that said “ICE out of LA!”.

Immigration and Customs Enforcement officers and agents executed search warrants at three locations, said Yasmeen Pitts O’Keefe, a spokesperson for Homeland Security Investigations.

But immigration advocates said they were aware of arrests at seven locations, including two Home Depots, a warehouse in the fashion district and a doughnut shop, said Angelica Salas, executive director for the Coalition of Humane Immigrant Rights, or CHIRLA.

In the fashion district, agents served a search warrant at a business after they and a judge found there was probable cause the employer was using fictitious documents for some of its workers, U.S. Attorney's Office spokesperson Ciaran McEvoy confirmed.

In Los Angeles, Mayor Karen Bass said the activity was meant to “sow terror.”

Federal immigration authorities have been ramping up arrests across the country to fulfill President Donald Trump’s promise of mass deportations.

Todd Lyons, the head of U.S. Immigration and Customs Enforcement, defended his tactics earlier this week against criticism that authorities are being too heavy-handed.

He has said ICE is averaging about 1,600 arrests per day and that the agency has arrested “dangerous criminals.”

AP video shot by Jae Hong