Columbia University threatens to expel student protesters who occupied administration building

NEW YORK — Dozens of protesters took over a building at Columbia University on Tuesday, barricading entrances and unfurling a Palestinian flag from a window in an escalation of demonstrations against the Israel-Hamas war on college campuses nationwide. The school promised they would face expulsion from the university.

The occupation at of the campus in New York — where protesters had shrugged off an earlier ultimatum to abandon a tent encampment Monday or be suspended — unfolded as other...