Three people with critical injuries are being transferred to hospital by helicopters after a multi-vehicle crash north of Taupō, which has blocked State Highway 1.
Fifteen people were injured in the crash, which involved a motorbike, three cars, a van and a small truck.
St John ambulance spokesman Gerard Campbell said emergency services were called to the crash site at about quarter past 12.
"We have sent three ambulances and three helicopters to the scene and we have 12 patients that are a mix of moderate, some minor injuries, and three patients who are in a serious condition."
The most seriously injured patients were being airlifted to Waikato Hospital while the others were going to Tokoroa or Taupo via ambulance, he said.