Citing an online threat of gun violence found by the FBI, the University of Chicago is suspending classes Monday, the university said in a statement Sunday evening. The school will increase security, and armed police will be present on campus. The school also said its security personnel remain in contact with the FBI, which will continue to investigate the threat.

The University of Chicago Laboratory Schools, the University of Chicago Charter School campuses, the University libraries, the Quadrangle Club, and other campus facilities will be closed on Monday. The school’s medical center will remain open to patients, with added security measures in place.

On Sunday, the FBI alerted school officials to a posting made by an unidentified individual that specifically mentioned gun violence on the campus quad Monday morning. The specificity of the threat, along with a number of other factors, compelled the school’s president to suspend classes.

College campuses and other academic campuses have been the sites of dozens of acts of gun violence in 2015. According to the nonprofit Everytown for Gun Safety, there have been 45 school shootings recorded in the United States this year. Earlier this fall, students at Philadelphia-area colleges and universities were on alert after the FBI and ATF warned of possible gun violence, just weeks after a shooting at Umpqua Community College in Oregon shocked people across the country.