Columbia police are warning female college students to take extra precautions after a series of early-morning break-ins and sexual assaults.

Police suspect that six incidents between May 1 and May 9 in the central Missouri college town may be related. In each instance, a college-age woman reporting finding a male suspect who broke into her apartment or attempted to enter. The crimes included one sexual assault and a second attempted sex assault by an assailant with a knife.

A police news release notes that the crimes are similar to a series of break-ins and assaults in downtown Columbia and the East Campus neighborhood in 2013.

The suspect is described as a white male in his 30's who may wear glasses and is about 6 feet tall with an athletic build.