Explosion at Harvard Medical School appears to have been intentional, authorities say. No one hurt

Authorities say there has been an explosion at Harvard Medical School, but no one was injured

There was an explosion early Saturday at Harvard Medical School that appears to have been intentional, but no one was injured, authorities said.

A university police officer who responded to a fire alarm tried to stop two unidentified people who ran from the Goldenson Building before going to where the alert was triggered, university police said in a statement.

The Boston Fire Department determined that the explosion was intentional and officers did not find additional devices in a sweep of the building, police said.