Dozens of protesters have taken over a building at Columbia University in New York, barricading the entrances and unfurling a Palestine flag out of a window, as the UN human rights chief said he was “troubled” by how law enforcement has dealt with the recent wave of campus demonstrations. In the latest escalation of uprest on US campuses, video footage showed protesters on Columbia’s Manhattan campus locking arms in front of Hamilton Hall early on Tuesday and carrying furniture and metal barricades to the building. Protesters ignored the Monday ultimatum to abandon their encampment or risk suspension Pro-Palestinian protesters take over Columbia University building Columbia begins suspending pro-Palestine protesters after ultimatum ignored