Authorities Investigating Explosion at Harvard Medical School That ‘Appeared to Be Intentional’

An explosion struck a Harvard Medical School building — and arson investigators said the incident appeared to be intentional.

According to reports from NBC Boston, CNN and the Harvard Crimson, the Harvard University Police Department (HUPD) was first called to the university’s Goldenson Building — a medical school building located on the Boston campus’ main quad — at around 2:48 a.m. local time on Saturday, Nov. 1, after a fire alarm went off.

Police officers said they saw two people fleeing the building, and they found evidence of an explosion on the fourth floor.

The Boston Fire Department Arson Unit was called to the scene, and investigators confirmed to the outlet that they believe the explosion “appeared to be intentional.”

No injuries were reported. Police performed a sweep of the building, but did not find “any additional devices,” police told CNN.

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“The Harvard University Police Department is actively investigating this incident in coordination with local, state, and federal law enforcement partners,” university police told CNN.

An FBI spokesperson confirmed to the Crimson that the agency is assisting in the investigation.

Harvard University did not immediately respond to PEOPLE’s request for information.

A source familiar with the investigation told the New York Post that the explosive device was not a bomb, but they did not share any further details about the incident.

The HUPD is working with several local, state and federal agencies on the investigation. Anyone with information is asked to call them at 617-495-1796.