An NYPD officer accidentally fired his gun in Hamilton Hall during the evacuation operation on the Columbia campus on Tuesday, but no one was injured, CBS News reported.

The police authorities are now conducting an investigation into the circumstances in which the incident occurred

In a statement released Thursday night, the New York Police Department said an Emergency Services Unit officer was using a firearm equipped with a flashlight to shine a light on a specific spot and accidentally shot a frame against a wall.

Columbia University President Minouche Shafik called in the NYPD to help clear Hamilton Hall after protesters stormed inside the building late Monday night and refused to leave, staying there for the rest of Tuesday

NYPD officers were seen entering the campus on foot as well as entering the building through a second-story window.

American television networks then broadcast live footage of the arrests of several young protesters.