MINNEAPOLIS - Authorities are looking into whether the recent robberies of three University of Minnesota students are related.

The latest happened early Friday when a 19-year-old student was assaulted and robbed as a gun was pointed at his head north of Dinkytown near the campus.

Police say no one has been arrested.

Sophomore David Tork said Sunday that he and three men had passed each other on the sidewalk when Tork got punched in the face and thrown up against the wall.

Tork says a gun was held "a couple of inches" from his head. He says the suspects "were pulling stuff" out of his pockets.

It's at least the third such robbery of a student on or near campus in less than three weeks.