BOSTON (AP) — Two Massachusetts men have been arrested in connection with a weekend explosion at Harvard Medical School, authorities announced on Tuesday. The FBI’s Boston office revealed the arrests via social media in advance of a 1 p.m. news conference to provide further details.

The explosion took place early Saturday morning on the fourth floor of the Goldenson Building, a facility that houses labs and offices of the neurobiology department. Thankfully, no one was reported injured in the incident.

Officials from the medical school reported that the explosion caused no structural damage, adding that all labs and equipment were unaffected. The Boston Fire Department has classified the explosion as intentional, yet police indicated that their sweep of the building yielded no further explosive devices.

An officer responding to a fire alarm encountered two individuals fleeing the scene, prompting a thorough investigation by campus police. The situation unfolds amidst heightened security measures and an investigation into the motives behind the attack.