Police want to speak to the driver of a van after two people died in a head-on crash on State Highway Three near Marton this afternoon.
Police confirmed two occupants of a blue Holden towing a trailer died at the scene after it crashed into a silver Mazda car at the intersection of State Highway Three and Williamson Line around 4pm.
Police suspect a third vehicle, a white van, may have been involved and would like to speak to the driver.
Three other people in the Holden were taken to Palmerston North Hospital with moderate injuries.
A driver and passenger travelling in the Mazda were flown by the Palmerston North Rescue Helicopter to hospital, one with critical injuries.
Police said at this stage it appeared the two vehicles were involved in a head on crash. Both vehicles were extensively damaged.
Police described the crash as an "absolute tragedy" and urged drivers to drive with care to ensure they arrive safe wherever their destination may be.
Police are asking anyone who may have witnessed the crash or with information about the white van to contact Police on (06) 351 2535.
Alternatively, information can be provided anonymously via Crimestoppers on 0800 555 111.
Those who died in the crash have yet to be formally identified and next of kin have not yet been identified.
The Police Serious Crash Unit are investigating.