A school van with 10 Kohanga Reo pre-school children on board has rolled in Kaitaia.

Four people were taken to hospital, including a teenager with "moderate" injuries. Three pre-schoolers had minor injuries.

Ambulance service team leader Allan Rhodes said ambulance officers assessed all the occupants of the van at the scene, and took four to Kaitaia Hospital.

The cause of the crash is not yet known but police were investigating at the scene.