Brandeis University was closed to non-essential staff Wednesday after anonymous threats were emailed.
The Waltham, Massachusetts, university confirmed it is working with law enforcement to investigate the threat.
Residential students on campus were temporarily relocated to a secure facility, where they were provided with food and drinks. All non-essential employees were instructed to leave campus.
The campus reopened around 5 p.m. after a check of buildings by public safety personnel.
The school said the campus will operate as normal on Thursday, and the upcoming orientation and move-in schedule remains unchanged.