A person has been freed from their vehicle after a high-impact crash that caused a car engine to be ripped out of the bonnet.
Emergency services were called to the two-car crash at the intersection of Harmans Gorge Rodd and Woodstock Road at about 10am.
The crash happened between Oxford and Sheffield on the north side of the Waimakariri River.
A Fire and Emergency NZ spokesperson said a person was trapped but freed at about 10.50am.
An NZME reporter at the scene said the crash involved two cars.
The engine of one of the vehicles was ripped out by the impact.
A St John spokesperson said one person was airlifted to Christchurch Hospital in a moderate condition.
The Canterbury Westpac Rescue Helicopter, two fire appliances and five police vehicles are at the scene.