Mahmoud Khalil, a recent Columbia graduate and Palestinian who is in the country legally and holds a green card, was arrested by ICE over his role in pro-Palestinian activism.

Federal immigration authorities arrested a Palestinian graduate student who played a prominent role in last spring’s anti-Israel protests at Columbia University, according to his attorney.

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.