Columbia University urges students to reconsider travel plans after arrest of graduate

Columbia University has called upon international students and scholars to avoid unnecessary travel, following the arrest of Mahmoud Khalil. The recently-graduated student was detained by immigration authorities for participating in protests against Israel on the institution's campus.

The university issued a statement on Monday citing reports about possible new federal travel bans, warning that visa delays or entry restrictions could prevent return to the US.

Khalil was detained by Immigration and Customs Enforcement agents, who said they were revoking his green card, when he arrived at his home at a student resident facility with his wife, who is eight months pregnant.

Meanwhile, the Huffington Post reported on Tuesday that 14 US representatives sent a letter to the secretary of homeland security, calling for the immediate release of the Palestinian activist.