At approximately 7:55 p.m., the University's Department of Public Safety received a report of shots fired in Nassau Hall.
Princeton University tweeted the following, "Public safety has received a report of gunshots at Nassau Hall. Princeton Police responded; no one hurt. DPS says avoid area."
The University sent out an emergency alert informing the community about the incident.
The all-clear was given around 10:30 p.m.
No injuries were reported.
Officers from DPS, Princeton Police Department, and the Mercer County Sheriff's office are investigating.