CHICAGO — The University of Chicago announced Sunday that all classes and other activities planned for Monday on its Hyde Park campus will be canceled after FBI counterterrorism officials informed the university of a gun violence threat to the campus.

University President Robert Zimmer sent an email to students and staff warning them of a threat posted online by an unknown individual, which specifically mentioned “the campus quad” at 10 a.m. Monday. Zimmer asked staff and faculty members who do not have emergency duties or patient care responsibilities to not come to the Hyde Park campus. Students who reside on campus were told to contact their resident heads and “to remain indoors as much as possible if they are on campus.”

“Based on the FBI’s assessment of this threat and recent tragic events at other campuses across the country, 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,” Zimmer said in the email.

In response to the threat, the university will bolster the police and security presence on and around campus, including personnel with visible weapons as the university keeps in close contact with the FBI, which is continuing to investigate the threat, Zimmer said.

One U. of C. student, who described the quad as “very busy” on Monday mornings, said students coming back from Thanksgiving holiday were stunned to learn of the threat via email and text from the university.

“I’m not going down there tomorrow, and I don’t have plans on going down there on Tuesday,” said the student, who only wanted to be identified as Will. “For a threat like this, I want to give a few days to cool off. I think it’s pretty extraordinary that the president interceded and canceled everything. I think that suggests something pretty serious is happening.”

The University of Chicago Laboratory Schools, the university libraries, the Quadrangle Club and other campus facilities also will be closed Monday. The University of Chicago Medical Center will remain open to patients with additional security measures.