The University of Chicago is cancelling all classes and activities on its main campus Monday following an online threat of gun violence.

The university says in a statement Sunday night that a threat from an unknown person was passed on to the university by the FBI. The threat mentioned the campus quad, a popular gathering place, and a time of Monday morning at 10 a.m., the statement says.

Faculty, students and non-essential staff are asked to stay away from the Hyde Park campus on Chicago's South Side Monday. Students in college housing are asked to stay indoors.

The university says: "We have decided, in consultation with federal and local law enforcement officials, to exercise caution by canceling all classes and activities on the Hyde Park campus through midnight on Monday."