Princeton University evacuated its New Jersey campus on Tuesday after receiving an unspecified bomb threat.
"There has been a bomb threat to multiple unspecified campus buildings," the school said in a press release. "Please evacuate the campus and all University offices immediately and go home unless otherwise directed by your supervisor. Public Safety officers and Princeton Police will direct drivers leaving the campus and those without cars will be directed to evacuation sites. You will receive an update later today. Do not return to campus for any reason until advised otherwise."
The school issued a similar alert on Twitter.
In an email to Yahoo News, Martin Mbugua, director of media relations and Princeton University spokesperson, confirmed the school had received a threat. He did not provide additional details.
The University's Department of Public Safety is investigating the threat with local, state and federal law enforcement agencies, the school said early Tuesday afternoon. Bomb-sniffing dogs were brought in, but as of 3:30 p.m., no explosives had been found. University officials said they were hoping to reopen the campus later Tuesday.
The Ivy League institution is currently on its summer session. Commencement was held on June 4.
Princeton, the fourth-oldest college in the United States, has more than 1,100 faculty members, 5,000 undergraduate students and 2,500 graduate students, according to its website.
But according to Princeton's Twitter feed, "most students left campus days or weeks ago."
Local police assisted Princeton University police with the evacuations, which snarled traffic in town.
A spokesman for Gov. Chris Christie told Reuters that the governor was not in Princeton, which is home to the executive mansion, Drumthwacket.
Tuesday's incident at Princeton comes on the heels of a pair of reported bomb threats. A Southwest Airlines flight from Los Angeles to Austin, Texas, was diverted to Phoenix after someone called in a bomb threat, the Associated Press said. The plane landed safely and no explosives were found.
Early Tuesday morning, Richmond International Airport closed and evacuated its terminal after receiving a threatening phone call. The terminal was reopened after a sweep found no explosives.