Large numbers of New York City police officers begin entering Columbia University campus

New York City police officers enter Columbia University amid pro-Palestinian protests, escalating tensions on campus.

Large numbers of New York City police officers entered Columbia University late April 30, hours after the mayor said a pro-Palestinian protest that has crippled the Ivy League school for two weeks “must end now.”

The officers took protesters into custody after the university called in police to end the pro-Palestinian occupation on the New York campus.

The scene unfolded shortly after 9 p.m. as police, wearing helmets and carrying zip ties and riot shields, massed at the Ivy League university's entrance. The demonstrators had occupied Hamilton Hall, an administration building on campus, more than 12 hours earlier, spreading their reach from an encampment elsewhere on the grounds that's been there for nearly two weeks.

Shortly before officers entered the campus, the New York Police Department received a notice from Columbia authorizing officers to take action, a law enforcement official told The Associated Press. The official was not authorized to discuss details of the matter publicly and spoke on condition of anonymity.

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The NYPD's move came hours after the department's brass said officers wouldn’t enter Columbia’s campus without the college administration’s request or an imminent emergency.

Columbia's protests earlier this month kicked off demonstrations that now span from California to Massachusetts. As May commencement ceremonies near, administrators face added pressure to clear protesters.