Boston: An employee was slightly injured when a package exploded on the campus of Northeastern University in Boston on Tuesday evening. Northeastern is a private university in downtown Boston with about 16,000 undergraduate students.

Another suspicious package was found near a prominent art museum.

The FBI took over the investigation.

The exploded parcel was one of two reported to the police later in the evening. The bomb squad defused a second package found near the city's Museum of Fine Arts on the outskirts of Northeastern's campus.

NBC Boston reported that the package that exploded went off as it was being opened near the university's Holmes Hall.

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.

Michael Davis, chief of Northeastern's police force, told reporters the campus was secure. Boston police did not say whether any other suspicious packages were found.

"We are monitoring the situation on campus and we are prepared to work with the university and our law enforcement on any prosecutions that may develop and offer a thorough investigation to determine exactly what happened," Suffolk County District Attorney Kevin Hayden said.

Harvard University and the Massachusetts Institute of Technology, across the Charles River that separates Boston from Cambridge, are increasing patrols on their campuses as a precaution and have asked students and faculty to report anything suspicious, university officials said.

Tuesday's blast was one of the first major scares in Boston since 2013, when two bombs exploded near the Boston Marathon's finish line, killing three spectators and injuring more than 260 others.