Seven people have been injured in a crash which has closed State Highway 1 in Kekerengu, north of Kaikōura.
Police said the crash was reported shortly after 1.30pm and involved two vehicles.
Police said one person is in a critical condition, three people are in a serious condition, and three people are in a moderate condition.
Hato Hone St John said they were notified of an incident along near Kekerengu at 1.31pm.
"We responded with three ambulances, two helicopters, one PRIME responder and an operations manager. This is an ongoing incident, and more information will be available shortly."
Diversions are in place, and the road is expected to be closed for a long period of time.
The Serious Crash Unit have been notified.