Typically, in such sweeps, teams of agents fan out in the early hours of the day to arrest people before they leave for work, after monitoring their movements in advance.
Among those arrested in Los Angeles, the agency said, was a Mexican gang member who entered the United States illegally. When agents encountered him, he rammed his car into multiple law enforcement vehicles in an effort to evade arrest. After he was arrested, agents found a loaded handgun in his pocket.
“Laws created under the guise to protect immigrants who are here to better their lives are being used by criminal elements to protect themselves,” said Jorge Field, assistant field office director for ICE in Los Angeles, adding that “having to make these arrests in public puts more people in danger.”
All told, agents arrested 167 undocumented immigrants in seven counties of Southern California, he said.
Honoring a campaign pledge, President Trump has made cracking down on illegal immigration a top priority. His attorney general, Jeff Sessions, has been a key proponent of punishing localities that refuse to cooperate with immigration authorities.
Mr. Sessions recently denounced a bill passed this month by the California Legislature to limit communication between federal immigration agents and state and local law enforcement, among other provisions.
The Trump administration has tried to withhold federal money to sanctuary cities, only to face several challenges in court.
A federal judge in Chicago this month blocked a Justice Department policy that would require Chicago to cooperate with federal immigration authorities if the city wished to receive public funds for safety. The preliminary injunction applied to cities nationwide.
What constitutes a sanctuary city is loosely defined, but many cities have said that cooperating with ICE undermines public safety because doing so erodes trust between police and immigrant communities.
In March, Mayor Eric Garcetti of Los Angeles signed an executive directive titled “Standing With Immigrants: A City of Safety, Refuge and Opportunity for All,” which reasserted the city’s longstanding policy of not cooperating with federal immigration enforcement.
In response to the latest ICE roundup, a spokesman for Mr. Garcetti said the mayor “believes that the administration should focus its actions on people who have committed serious crimes or pose a threat to our national security.”
In Denver, which…