Two Massachusetts men have been arrested in connection with Saturday's explosion at Harvard Medical School , the FBI announced on Tuesday.

Two people were spotted fleeing the scene of the explosion, which occurred on the fourth floor of the Goldenson Building just before 3 a.m., according to the Harvard University Police Department.

No injuries were reported, police said.

Harvard University Police Department

Authorities will announce more details at a news conference at 1 p.m. ET on Tuesday.

This is a developing story. Please check back for updates.

See Full Page