The agency called in the Tampa Police bomb team to investigate the person's belongings. That happened about 90 minutes after they received an off-campus call about the possible gunman.
An alert was posted on the school's Web site Monday afternoon said people on campus should stay inside and lock their doors while officers searched the area.
A subsequent alert - posted at 3:29 p.m. EDT - said a white male was spotted near a university building carrying a black puppy and a large knife. Security officers were investigating.
Police also said they received more information about someone on a bus and were attempting to locate the person and secure the area. It is not clear if that is the same person reportedly seen with the knife on campus.