RICHFIELD, Minn. (AP) _ Authorities say they have not established a motive in a shooting outside a suburban Minneapolis school that left one student dead and an another critically injured.

The students were shot Tuesday outside South Education Center in Richfield, a suburb just south of Minneapolis. Police arrested two teen suspects at separate locations later in the day.

Richfield Police Chief Jay Henthorne said five people were involved in the ``horrific, tragic incident,'' but didn't give further details other than to say it was a disagreement among ``acquaintances.''

A 15-year-old student was killed and a 17-year-old student was critically injured. A third student was hurt but Henthorne said he wasn't sure whether the injuries were from gunfire.