Protesters clashed with police on Friday evening outside a federal detention center in Los Angeles after U.S. immigration authorities arrested more than 40 people.

Dozens of demonstrators gathered outside the center where they believed those arrested had been taken, chanting “Free them all".

Law enforcement officers carrying riot shields were seen using pepper spray, flash bangs and tear gas to try to disperse the crowd.

Forty-four people were arrested on immigration violations across multiple locations in Los Angeles, a spokesperson for Homeland Security Investigations said.

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.”

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