A University of Minnesota student was robbed at knifepoint late Monday night just after she withdrew money from an ATM along Washington Avenue, and the perpetrator fled on a light-rail train as it stopped in front of campus police headquarters, authorities said Tuesday.

The crime, reported in a campuswide alert by U police, occurred about 11:30 p.m. Monday along Washington near Walnut Street, just west of campus.

According to the alert:

The 20-year-old student left the ATM and was walking west when a man approached from behind and asked for directions. He then pulled a knife and threatened to harm her if she screamed.

The woman gave the man the money she had withdrawn. She suspects he had followed her to the ATM because he "was lurking around her prior to the incident," a city police incident report read.

The suspect boarded an eastbound light-rail train at the Green Line's East Bank Station.

The U's police headquarters is immediately north of that platform on Washington, a busy thoroughfare with restaurants, a hotel and stores nearby.

The woman described the suspect as black, 20 to 25 years old, 6 foot to 6 foot 3, with a thin build, brown hair, brown eyes and a dark complexion. He was wearing a dark green T-shirt and shorts. She described the weapon as a kitchen knife roughly 8 inches long.

Because the robbery occurred just off campus, Minneapolis city police are investigating. Anyone with information is asked to call the Minneapolis police tip line at 612-692-8477.

Paul Walsh • 612-673-4482