New York’s Columbia University is taking measures to secure the campus as the new school year begins, fearing a return by large-scale anti-Semitic riots like the ones that rocked the campus last year.

Fox News reports that, among other measures, the university will initiate a lockdown to keep “non-affiliates” off of the campus. When police arrested dozens of rioters who broke into the university’s Hamilton Hall, about half of the culprits were non-students. The agitators smashed windows, barricaded doors, and wore masks to cover their identities as they attempted to take over the building as a means of forcing their demands to be met. They also set up a tent encampment that lasted for several weeks before it was also broken up by police.

“This change is intended to keep our community safe given reports of potential disruptions at Columbia and on college campuses across the country as we approach the beginning of the new school year,” said the university’s chief operating officer Cas Holloway in a statement. “We are particularly concerned about non-affiliates who may not have the best interests of the Columbia community in mind.”

The new rules will be implemented as part of the university’s “orange rules,” a level of security enforcement based on a color scale similar to traffic lights. When the rules are “green,” the outdoor campus is free for anyone to access while a student ID is required to enter buildings. Under “yellow” rules, some entrances and exits may be blocked off even though the campus is still open to the public. Orange is placed between yellow and “red” rules in terms of severity. Under red, no guests are allowed on-campus at all; only students and staff are allowed onto the campus.

The lockdown will be enforced by ID checks at entrances and exits, with access being forbidden to anyone who does not have a student ID or guest registration. These rules were implemented on Monday, and will be continuously enforced until further notice.

“President [Minouche] Shafik and the university leadership team take their responsibility for the safety and well-being of the entire university community seriously,” said a university spokesman in a statement. “The university has been using the summer both to learn from the lessons of the past academic year and plan for the next one.”

In the immediate aftermath of the terrorist attacks against Israel by the Islamic terrorist group Hamas on October 7th, 2023, anti-Israel protests began breaking out in the United States, particularly on college campuses. Columbia University was widely seen as ground zero for these anti-Semitic demonstrations, being among the very first colleges to see such violence, as well as being among the absolute most violent riots in the country.