Columbia University, Cornell University and Brown University said their campus buildings had to be cleared for re-entry hours after reports of bomb threats on Sunday afternoon.

All three Ivy League schools said the threats were deemed not credible by officials.

Law enforcement swept several buildings at Cornell, and the university asked students to avoid central campus “out of an abundance of caution,” according to an alert issued by the Ithaca, New York-based school.

Earlier, Brown and Columbia ordered evacuations and police investigated multiple campus buildings following bomb threats. There were reports on Twitter of threats of explosives on campus and against law enforcement.

New York Gov. Kathy Hochul said her team was monitoring the situation at Cornell and Columbia, and stood ready to offer support.

Yale University was the subject of a bomb threat on Friday. Campus buildings were cleared for re-entry after a few hours.