A student has been injured in an end-of-year prank gone-wrong, where a group of teenage girls rode through a rival school topless on motorbikes.
The rider, from Waikato Diocesan School for Girls, was wearing only underwear and a helmet when she ran over the leg of a boy from Hamilton Boys' high School, Fairfax reports.
It is understood six senior students were involved in the prank, riding through the boys' school shortly after midday on Wednesday.
Police were called and the boy, suffering a leg wound, was taken to hospital by ambulance.
At the time he was running towards the motorbike to try to knock the driver off, witnesses say.
Waikato Diocesan School for Girls principal Mary Curran told Fairfax the behaviour was "unacceptable" and "school process" would be followed.