Two people have been airlifted to hospital after an incident in which a group of 22 students and three teachers got into trouble in Auckland's Waitakere Rangers.
It is understood two 16-year-olds were taken to hospital to be treated for hypothermia.
The group activated an emergency locator beacon tonight, and emergency services -- including the Wespac Rescue Helicopter -- were rushed to the area.
The group got off-track while reportedly tramping the Muir Track near Karekare Beach, south of Piha.
Ambulance and search and rescue staff are with the rest of the party and assessing options for them to walk out tonight.
Meanwhile, a 17-year-old girl from a separate group of six trampers has suffered knee and hip injuries on the Waitakere's Twin Peak Track, near Huia.
Police say the teenager is unable to walk out and emergency services have been called.