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legal resident of the United States, was arrested and detained by federal agents Sunday, after his green card was revoked by the Trump administration.

Nearly 100 people were arrested after protesters gathered at Trump Tower in Manhattan Thursday to denounce the arrest of Mahmoud Khalil, a Palestinian activist detained by ICE over his involvement with pro-Palestinian demonstrations at Columbia University.

Trump criticized universities across the country over pro-Palestinian protests, which he said created an unsafe environment for Jewish students.