A Coromandel student is critical after an alleged assault outside the school gate. 

A notice put out to parents and caregivers by Coromandel Area School yesterday said two students were involved in a "serious harm incident" just after 3pm. 

"One student was airlifted to hospital and police are currently investigating this incident," the school's presiding member/chairwoman, Abby Morgan, said in the notice. 

"We are not able to make any further comments at this stage. We will provide further information if, and when, we are able to. 

"Supporting students through this will be our priority. Classes will run as usual tomorrow but plans are in place to support our staff and students through this. Take care and be kind," Morgan said. 

A police spokeswoman said police were advised of the serious assault and one person was taken to hospital with serious injuries. 

"Ambulance and a helicopter arrived on scene to assist. There was one victim involved. They are currently in a stable but critical condition. Inquiries are still ongoing," the spokeswoman said. 

A St John spokesperson said an ambulance and a rescue helicopter went to the scene and a person was taken to Waikato Hospital.