Mohsen Mahdawi, an organizer of pro-Palestinian demonstrations last year at Columbia University, was detained by immigration officials on Monday after arriving for an appointment in Vermont that he thought was a step toward becoming a U.S. citizen, his lawyers said.

Hours later, Mr. Mahdawi’s mother, older sister and lawyers were scrambling to find him after his abrupt detention at an immigration center in Colchester, Vt. His lawyers requested a temporary restraining order to prevent federal officials from transferring him to a more conservative jurisdiction — a tactic used in the detention and attempted deportation of at least four other college demonstrators.

A Vermont federal judge, William K. Sessions III, swiftly granted that request, ordering that Mr. Mahdawi, an outspoken critic of Israel’s military campaign in Gaza, not be removed from the United States or transferred out of Vermont until he orders otherwise. His lawyers said that as of Monday afternoon, they had confirmed that he was still in Vermont.

“This is their M.O.,” Mr. Mahdawi’s lawyer, Luna Droubi, said. “They just continue to hide the individual to the point where their attorneys can’t quite understand or identify where to file. And so, you know, we’re operating blind, and they have all the information, and yet we’re tasked with attempting to file in the right jurisdiction.”

A green card holder for the past 10 years, Mr. Mahdawi is the latest Palestinian student to be caught in the Trump administration dragnet that has been targeting foreign students involved in pro-Palestinian organizing on U.S. college campuses.

Mr. Mahdawi was born and raised in a refugee camp in the West Bank, where he lived until he moved to the United States in 2014, according to a petition filed by his lawyers on Monday demanding his immediate release. His arrest was first reported by The Intercept.