A pro-Palestinian student protester at Columbia University has been detained by US immigration officials, according to his lawyer. The student, Mahmoud Khalil, had his student visa revoked, but his lawyer claims he is a legal permanent resident with a green card and married to an American citizen. It is unclear where Khalil is currently being held, but there are reports that he could be transferred as far away as Louisiana. This detention comes after President Trump's executive order warning of deportations for those involved in pro-jihadist protests and Hamas sympathizers on college campuses.