Two of those shot are Muskegon Heights students, according to a statement from Superintendent Alena Zachery-Ross.
Thomas said his office received information suggesting an incident would occur Tuesday after a dispute in nearby Grand Rapids last week.
Several people involved in that dispute were expected to attend the basketball game between Muskegon Heights Academy and Grand Rapids Ottawa Hills — to “settle the score, whatever that means.”
Extra police, including county and state police, were sent to the game. The four people shot were denied entry to the school and walked to a nearby football field, where the shots were fired.
Police did not release the names of those involved. Classes at the high school were canceled Wednesday.
