A Fire and Emergency New Zealand spokesman said two appliances had attended the incident, one from Foxton and the other from Waitarere Beach.
He believed people were being extricated from both vehicles and was unsure at the extent of injuries.
UPDATE 6:55PM Due to this serious #crash in Foxton, the road is now CLOSED at the intersection with Newth Road. Please follow directions of emergency services on-site or #delay your journey. ^EL https://t.co/OkGVXH80SC
A Fire and Emergency NZ spokesman said an ambulance and a helicopter were also on the scene.
Police said a diversion had been put in place at Te Horo Beach and Te Hapua. "However, emergency services are working to clear the road and expect it to be reopened soon."