Police are investigating an incident involving pupils from Waitaki Boys' High School and St Kevin's College that resulted in one pupil allegedly being struck by a car.
The incident, believed to have involved members of both schools' First XV rugby sides, took place at St Kevin's College grounds on the evening of July 4.
Sergeant Tony Woodbridge, of Oamaru, said a group of pupils from Waitaki Boys' was believed to have driven to St Kevin's to throw eggs at the school's boarding hostel building.
The Otago Daily Times understands another male, who was not a pupil at Waitaki Boys', was part of the group.
The group was confronted by several St Kevin's pupils, who threw eggs and rocks at the vehicle, Sgt Woodbridge said.