The University of Minnesota is closing three buildings on campus due to a threat of a shooting at the buildings.

The university says Thursday that it's closing the Carlson School of Management, Hanson Hall and the Hubert H. Humphrey Center.

All classes and activities beginning at or after 3:45 p.m. Thursday are canceled. The buildings will close at 4:30 p.m.

University Police Chief Greg Hestness says officials are erring on side of caution. Police are investigating the threat.

University officials added the building closures had nothing to do with the swine flu virus.