Pokuru Road was closed to allow Serious Crash Investigators to conduct a scene examination and determine the cause of the collision.
Victim Support attended at the scene to provide support to parents, pupils and teachers of the school.
The Pokuru School website says the children are from farming families in the Pokuru, Te Kawa and Te Mawhai areas and a number of children live in Te Awamutu and commute to the school daily.