Three people have been injured, two seriously, after two vehicles collided on Cosgrave Rd in Papakura, south of Auckland.
A St John spokesman said three ambulances were dispatched to the crash around 4.20pm.
Paramedics assessed five people at the scene.
Two patients with serious injuries and another with moderate injuries were taken to Middlemore Hospital by ambulance, the spokesman said.
Two other people had minor injuries.
A van had flipped on its roof, a police spokeswoman said.
The southbound lane was blocked and diversions were being set up.