Two cars were involved in a head on collision in the Karangahake Gorge, near Waihi, earlier this afternoon.
Waikato police have asked all travellers to avoid using State Highway 2 Karangahake Gorge between Waihi and Paeroa for the next four to five hours.
Trustpower TECT Rescue Helicopter was dispatched to the gorge, where three people had received critical injuries.
Trustpower TECT Rescue Helicopter base manager Liam Brettkelly said NZ fire service had to cut some of the victims from the wreckage.
Two patients were airlifted to Waikato hospital by the Auckland and Waikato Westpac helicopters.
The third, a 17-year-old Auckland woman, was airlifted by the Trustpower TECT rescue helicopter to Tauranga hospital in a serious condition.
Waikato police have asked all travellers heading to the Bay of Plenty have been asked to use the Kopu Hikuae Rd from Thames or State Highway 29 Kaimai and the reverse if heading to Waikato.
This was the second head-on crash in the same spot today, the first occurring around mid morning.
Police have also asked drivers take care and attention when driving as the roads are busy and patience is required.