CAMBRIDGE - Hundreds of students and staff at Harvard University received emails on Friday from a sender who threatened to come to the Ivy League school "tomorrow" and shoot them, according to campus police.
The Harvard University Police Department said it could not verify that the threat was authentic but said it would step up security over the weekend around the university's campus, centred in Cambridge, Massachusetts, just outside Boston.
University police said they had alerted the Federal Bureau of Investigation and local law enforcement.
Boston-area residents have been on an elevated state of alert since a pair of homemade bombs were set off at the city's marathon in April 2013, killing three people and injuring 260.
Parts of the elite university were also evacuated in December when the school received a bomb threat from a person who turned out to be a student trying to get out of taking a final exam. That student was later arrested and is facing federal charges of making a hoax bomb threat.