Police have begun arresting demonstrators from a Jewish group who filled the lobby of Trump Tower to denounce the immigration arrest of Mahmoud Khalil, a pro-Palestinian activist who helped lead protests against Israel at Columbia University.

The arrest of pro-Palestinian organizer Mahmoud Khalil has become a flashpoint on the rights of legal U.S. residents and free speech.

Federal agents arrested Mahmoud Khalil, a Palestinian student who played a major role in last year's protests at Columbia University, students said.