Students marched from Washington Square Tuesday to protest the arrest of Mahmoud Khalil​, a pro-Palestinian activist at Columbia University. Some arrests were made at City Hall.

The Department of Homeland Security claimed that Columbia University anti-Israel activist Mahmoud Khalil “led activities aligned to Hamas, a designated terrorist organization."

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legal resident of the United States, was arrested and detained by federal agents Sunday, after his green card was revoked by the Trump administration.