Police entered Hamilton Hall from a second-floor window after using a mobile ladder to access the facility just after 9 p.m. local time (0100GMT Wednesday). Television footage aired by CNN showed dozens of officers in riot gear entering the building, with some carrying zip-tie restraints and heavy-duty bolt cutters.

At least one police bus filled with detained demonstrators was seen in video footage leaving Columbia's campus with police operations ongoing.
The building was cleared of demonstrators about two hours after the operation began, and over 100 people were taken into custody, according to multiple reports.
Protesters entered Hamilton Hall, which they have renamed "Hind's Hall" in memory of 6-year-old Palestinian Hind Rajab, who was brutally killed in Gaza, early Tuesday morning and maintained they would not leave the building unless their demands are met.
They and another group that has been staging an encampment on a Columbia lawn are seeking to have Columbia divest from Israeli firms and condemn Israel’s war on the Gaza Strip. Columbia President Minouche Shafik has maintained the school will not divest.
Columbia's protests began in April and have served as a flashpoint for the wider anti-war movement after Shafik asked the NYPD to deploy to the school's campus on April 18, when over 100 people were taken into custody in an attempt to clear an encampment.
Demonstrators quickly adapted, however, and opened a new sit-in on another university lawn.
This time around, Shafik requested that the NYPD maintain a presence on Columbia's campus until at least May 17 -- the day after the school's multi-day graduation concludes -- "to maintain order and ensure encampments are not reestablished."
"We trust that you will take care and caution when removing any individual from our campus. The safety and security of our community is our highest priority, especially for our students," she wrote in a letter to the NYPD that was circulated on social media and news outlets.
Bystander video footage from inside the campus depicted widespread chaos, however, with protesters being shoved and yelled at by law enforcement.
At least one protester was seen being dragged across the ground by a police officer. They are dragged out of frame, but are then seen rolling down a set of stairs after the camera pans, apparently screaming in pain, according to footage posted online by the Columbia chapter of Students for Justice in Palestine.
New York Representative Alexandria Ocasio-Cortez said that if any student is injured during the police activity, responsibility would fall on New York City Mayor Eric Adams and university leaders.
"Other leaders and schools have found a safe, de-escalatory path. This is the opposite of leadership and endangers public safety. A nightmare in the making. I urge the Mayor to reverse course," she wrote on X.
Columbia's faculty said ahead of the police entering campus that they spent the day attempting to diffuse the situation but were "rebuffed or ignored."
"We have been locked out of our campus and have demanded to be allowed back in, and have been rebuffed or ignored. This is not new. Columbia faculty have attempted for the past two weeks to intervene in the situation, only to be shut out by senior University leadership," the school chapter of the American Association of University Professors said in a statement.
"The NYPD presence in our neighborhood endangers our entire community. Armed police entering our campus places students and everyone else on campus at risk. That is why University statutes require consultation with faculty — statutes which appear to have been ignored since April 17, and again tonight," they added.

Dozens arrested after police clear Columbia University building held by pro-Palestine protesters