An evening at Columbia University that turned stormy

As a storm broke over New York, riot police mounted a tall ladder on a reinforced truck to penetrate a building at

Columbia University and clear out barricaded pro-Palestinian protesters.

Scores of armed, helmet-clad NYPD officers arrived in the north-west of Manhattan on Tuesday evening, accompanied by buses and trucks, as they set up barriers around the grounds of the prestigious institution.

Columbia, which counts 37,000 students and is typically open to the public, was entirely surrounded.