University of Minnesota police said the woman was walking through Anderson Hall when the man approached her, displayed his gun and demanded her laptop, the Minneapolis Star Tribune reported. He became angry when she handed him an empty bag, but fled when in the campus' tunnel system when she screamed, police said.
The would-be robber had not been caught, the newspaper said.
The university alerted students and others on campus via a text message at 3:20 p.m. CST and an hour later sent an update stating a search of the West Bank campus had been completed and there was no need to take shelter.
"This was an attempted robbery -- no shooting occurred," police said.
Daren Johnson, technical project manager for the Information Technology Office in College of Liberal Arts in Anderson Hall, told the Star Tribune the building was locked down after the holdup attempt.
Campus police described the gunman as a black, about 20 years old, 6 feet tall and wearing a black, puffy, hooded jacket.