Supervisors Jackie Fielder, Connie Chan and Shamann Walton were expected to speak at the rally with representatives of La Raza Centro Legal and the San Francisco Immigrant Legal and Education Network. The event follows reports of federal immigration agents in SoMa and the Excelsior neighborhood.

Witness video of an encounter at 360 Sixth St. showed three masked agents confronting a man in a suit. One plainclothes agent, wearing a red flannel shirt, displayed a gun as the man questioned the agents’ identities and repeatedly said he was a U.S. citizen, according to reports of the footage. Agents searched his pockets and handcuffed him as bystanders watched and recorded. The encounter lasted about five minutes.

It remains unclear why the man was detained. The San Francisco Public Defender’s Office was reportedly working to secure legal representation for him. The San Francisco Rapid Response Network also reported agent sightings in the Excelsior.

Supervisor Matt Dorsey, whose district includes the SoMa location, described the encounter as unacceptable. Mayor Daniel Lurie said the city’s sanctuary policies remain in effect and directed people seeking immediate legal support during an immigration enforcement encounter to the Rapid Response Network at 415-200-1548.

The hotline’s capacity is under pressure. Mission Action, the nonprofit that operates it, did not receive supplemental city funding it had expected this year. Executive Director Laura Valdez said the mayor’s office told the organization it had missed the proposal deadline; Valdez said Mission Action had not been given a clear deadline. The mayor’s office declined to comment.

The agents’ activity has not been linked to the Trump administration’s Operation Protect the Vote, which targets immigrants suspected of illegally voting. City officials and advocates have not said whether the SoMa detention was connected to that effort.