Two people have been injured in a single-vehicle collision on Mount Cook Road, Ben Ohau, Mackenzie District.
Emergency services were called at 12.05pm.
A St John ambulance spokesman told Chris Lynch Media they were notified of a motor vehicle incident on Mount Cook Road at 12:13 and responded two ambulances, one first response, one prime unit and two helicopters.
“We assessed and treated one patient in a serious condition who is being airlifted to Christchurch hospital, and one patient in a critical condition who is being airlifted to Dunedin hospital.
Motorists are advised to avoid the area.
NZTA said the serious crash happened near Boundary Stream bridge.
SH80 along Lake Pukaki, south of Glentanner/ Mt Cook in Canterbury has been closed.