A woman is believed to be in a serious condition after a crash near St Leonards this afternoon.
State Highway 88 has been closed and traffic has backed up after two cars collided about 3.20pm.
One of the cars is in the middle of the road and a woman was trapped inside.
Firefighters are cut the woman from the car and she was transferred to an ambulance.
Police said one person has been taken to hospital for further treatment and others are being treated on the scene.
The other vehicle has gone down a bank and is sitting near the railway line. The occupants are out of the car and appear to have minor injuries.
A detour using local roads is available for cars/light vehicles.
There is no alternate route for heavy vehicles the NZTA said.
The Police Serious Crash Investigation Unit has been called to the site and the Transport Agency will update the status of the highway around 5 pm.
Police said shortly after 4pm that traffic was being diverted to St Leonards Drive between Pukeko and Tui streets.
"St Leonards Drive is down to one lane in places, with contractors providing assistance with traffic control.
"Delays are expected and police ask motorists to drive with care.''