Federal prosecutors on Tuesday announced charges against 15 people accused of conspiring to impede federal officers during the Trump administration's controversial immigration crackdown in Minnesota, warning that additional arrests could follow.

At a Minneapolis press conference, U.S. Attorney Daniel Rosen said the defendants were linked to two Minneapolis-based groups associated with the anti-fascist movement known as antifa and allegedly coordinated efforts to obstruct "Operation Metro Surge," a federal immigration enforcement operation that deployed thousands of agents to the Twin Cities beginning in late 2025.

According to Rosen, the defendants used a variety of tactics to interfere with federal operations, including tracking agents, alerting neighborhoods to enforcement activity and using blocks of ice to slow government convoys.

Twelve suspects were arrested Tuesday, one was already in custody on unrelated federal charges and two remain at large.

Rosen signaled that the investigation remains active.

"If you are actively conspiring to impede law enforcement you ought to go on the assumption that we're watching, and we'll get you," he said.

The charges stem from Operation Metro Surge, which triggered widespread protests and community resistance after federal agents conducted large-scale immigration raids across Minnesota.

The operation became even more controversial after two people, Renee Good and Alex Pretti, were fatally shot by federal agents during enforcement actions, sparking additional demonstrations.

The prosecution is the latest in a broader federal effort to crack down on opposition to immigration enforcement.

Earlier this year, the administration secured convictions in cases tied to anti-ICE protests in Texas and Washington state, while other conspiracy cases have been brought in Illinois and Minnesota.

Federal officials have long indicated they were investigating those organizing resistance to immigration operations. During the Minnesota crackdown, Border Czar Tom Homan publicly vowed accountability for those interfering with enforcement efforts.

"They'll be held accountable," Homan said at the time. "Justice is coming."

The charges also come as the Trump administration intensifies its focus on antifa following the president's September executive order directing federal agencies to "investigate, disrupt, and dismantle" organizations and individuals linked to the movement.

Outside the federal courthouse Tuesday, dozens of demonstrators protested the arrests, carrying signs reading "Protesting is not a crime" and "Stop FBI entrapment."

Critics argue the prosecutions represent an attempt to criminalize opposition to federal immigration policies, while Rosen maintained the case is focused on alleged efforts to obstruct law enforcement operations rather than protected political speech.