Federal agents turned up in downtown Los Angeles, where Gov. Gavin Newsom was delivering a speech, and detained at least one person in the latest high-profile immigration enforcement operation in the city.

The armed and masked agents assembled outside the museum where the governor was speaking. Mayor Karen Bass of Los Angeles called it “a provocative act.”

Governor Gavin Newsom unveiled his campaign effort to shrink California’s Republican congressional seats as federal border patrol agents swarmed outside the raucous event in Los Angeles.