Standing with their backs to the U.S. Citizenship and Immigration Services office in downtown Minneapolis, the protesters shouted one message: An injury to one student is an injury to all.

The University of Minnesota Graduate Labor Union-United Electrical Local 1105 organized the protest Saturday, one day after U officials said that U.S. Immigration and Customs Enforcement (ICE) agents had detained an international graduate student. Participants included dozens of academics representing graduate students in Minnesota, Arizona and California, many of them waving red and black flags as they marched downtown.

"I'm not an international student, so I don't want to speak on behalf of international students, but yes, people are terrified," Local 1105 President Abaki Beck said. "There is quite a bit of fear and uncertainty, and trying to figure out how to organize and move forward and stand collectively."

Summer Pappachen, a doctoral student at Northwestern University in Chicago, hollered: "When students are under attack, what do we do?" Drums beat as the protesters responded, "Stand up, fight back!"

U President Rebecca Cunningham told students, faculty and staff of the student's detainment in a statement released Friday. Cunningham said that ICE agents detained the student at an off-campus residence without U officials' prior knowledge or cooperation. The situation, she said, was "deeply concerning."

ICE officials did not respond to requests for comment Saturday. The Graduate Labor Union plans to host another rally Monday at Morrill Hall on the U campus.

U officials have not identified the detainee, who is a student at the Carlson School of Management and has asked for privacy. The student is receiving legal representation from the University Student Legal Service office.

Andria Waclawski, the U's public relations director, said that state and federal privacy laws bar school officials from sharing a lot of information in such cases.

"We're following the student's lead and respecting their request for privacy," Waclawski said.

She said that concerned students may want to turn to the university's Rapid Response website, "for anyone in our community that's affected by these policy changes or other contacts from officials."

Local officials have expressed concern. In a social media post Friday on X, Gov. Tim Walz said he had contacted the U.S. Department of Homeland Security for more information. U.S. Rep. Ilhan Omar said on X that her office had been in touch with the student's counsel.

"International students are huge assets to the University of Minnesota," U.S. Sen. Tina Smith said on Facebook. "They move thousands of miles away from their families and support systems to learn from the best and the brightest. I can't imagine how terrified they are after learning ICE has detained one of their classmates. ... We need answers on exactly what is happening."

Federal agents have reportedly arrested a number of international students without charges in recent weeks, alarming academics and local officials. The Trump administration has particularly targeted people expressing pro-Palestinian views, though it wasn't known whether that was the case with the detained U student.

"Even if the person who is speaking is an international student who is speaking on a visa, the Constitution covers them," said Carl Rosen, general president of the United Electrical, Radio & Machine Workers of America.

"We're standing up now," Rosen said. "We're asking everyone else in civil society to stand up with us and demand rights for everyone. Because when rights are taken away from anyone, everyone ends up losing them."

Elliot Hughes of the Minnesota Star Tribune contributed to this report.