Mahmoud Khalil, a 29-year-old legal resident of the United States, was arrested and detained by federal agents Sunday, after his green card was revoked by the Trump administration.

Agents told Mahmoud Khalil’s attorney that they were revoking Khalil’s green card. He is legally considered a permanent resident.

Mahmoud Khalil is being detained as his lawyer fights for his release. A Palestinian protest leader at Columbia University was arrested by Department of Homeland Security agents Saturday night despite having a green card, his attorney said.