Several campus buildings at Harvard University were placed on a lockdown around 12:30 p.m. on Monday, after the Ivy League school received an "unconfirmed bomb threat."

Officials shut down the Science Center and implemented a mandatory evacuation in Sever, Emerson and Thayer Halls, while Cambridge Police and bomb squad unit searched the buildings. People were also prohibited from accessing the Harvard Yard.

Cambridge Police said the treat was sent via an anonymous blog post Monday morning, claiming someone was planning to bomb "cambridge mass city schools," reports Boston.com. As a result, all school buildings were searched, but superintendent of schools Jeffrey Young said nothing "unusual" was found.

Shortly before 2 p.m., Harvard executive vice president Katie Lapp issued a statement to Harvard students, faculty and staff. She said, "Nothing to substantiate the emailed threat has been found. Harvard is working with local and federal law enforcement officials to investigate the source of the threat, which has not yet been determined."

The letter also stressed the "safety and security of members of the Harvard community" as a top priority in light of the terrorist attack in Paris on Friday.

"In the wake of recent tragic events in locations ranging from Paris to Beirut and beyond, we understand that this type of threat will cause great anxiety for many across our campuses. We will continue to be vigilant as we carry on Harvard's mission of expanding and disseminating knowledge," the statement reads.

At 3:25 p.m., officials posted another statement on the school website, notifying students that some of the mandates had been lifted.

"The searches of Emerson and Sever Halls have been completed. Both buildings are open. Restrictions on access to the Yard have been lifted," reads the statement. "The searches of Thayer and the Science Center continue. We will send updates when information becomes available."

Meanwhile, WBUR reported that classes were cancelled at Cape Cod Community College Monday morning due to a threat, while Fitchburg State temporarily evacuated its McKay campus reports MassLive.com.