GRAND FORKS (AP) - A University of North Dakota airplane veered off the runway at the Grand Forks airport, school officials said.

The student pilot was not hurt but the Piper Warrior plane was damaged Thursday morning, said Dana Siewert, director of aviation safety at UND.

The plane left the runway and traveled about 60 yards on its wheels before coming to a stop in tall grass, Siewert said

It's not clear if the accident was caused by a pilot error or a mechanical problem, Siewert said. The cause is under investigation.

A UND airplane crashed in central Minnesota last fall, killing a student and flight instructor. School officials said the plane likely went down after colliding with geese.

The National Transportation Safety Board is still investigating.

Student Adam Ostapenko, 20, of Duluth, Minn., and instructor Annette Klosterman, 22, of Seattle died when the plane crashed in a swampy area in central Minnesota on Oct. 23, 2007. They were on a routine training flight from St. Paul, Minn., to Grand Forks when the plane went down near Browerville, Minn.

In December 2006, UND students were killed when a single-engine Cessna left the Crookston, Minn., airport and crashed into a farm field.

Pilot Jacob Rueth, 18, of Orland Park, Ill., and passenger Jacob Allen Sundblad, 19, of Annandale, Minn., were killed.

Last June, a UND student and flight instructor escaped injury when the helicopter they were in overturned before takeoff.