A package exploded on the campus of Northeastern University in Boston late Tuesday, and the college said a staff member suffered minor injuries.
Authorities said another suspicious package was found near a prominent art museum and the FBI was assisting with the investigation.
The parcel that blew up was one of two that were reported to police early in the evening. Boston's bomb squad neutralized a second package near the city's Museum of Fine Arts, which is on the outskirts of the Northeastern campus.
NBC Boston reported that the package that exploded went off as it was being opened near the university's Holmes Hall, which is home to the university's creative writing program and its women's, gender and sexuality studies program. It said the FBI was assisting the investigation.
Authorities declined to elaborate, but Northeastern spokesperson Shannon Nargi said in a statement that an unidentified university staff member suffered minor injuries to his hand in the explosion. Felipe Colon, a Boston police superintendent, later described the victim as a 45-year-old man.
Police converged on the campus shortly before 7:30 p.m., and the university asked students who had gathered for an evening journalism class at the hall to evacuate the building.
Northeastern is a private university in downtown Boston with about 16,000 undergraduate students. WCVB-TV said one of its reporters, Mike Beaudet, was teaching a class there at the time. Beaudet told the station his class was moved outside but that neither he nor his students heard an explosion.
Michael Davis, chief of Northeastern's police force, told reporters the campus was secure. Boston police didn't say whether any other suspicious packages were found.
"We're monitoring the situation at Northeastern and we're ready to work with the university and our law enforcement partners on any prosecutions that may develop," Suffolk County District Attorney Kevin Hayden said, promising "a comprehensive investigation to determine exactly what occurred here."
Harvard University and the Massachusetts Institute of Technology, both on the other side of the Charles River separating Boston from Cambridge, said they were increasing patrols on their campuses as a precaution and urging students and faculty to report anything suspicious.
Tuesday's explosion marked one of the first big scares in Boston since 2013, when two bombs planted near the finish line of the Boston Marathon killed three spectators and wounded more than 260 others.