A police officer said the Multi Utility Vehicle, travelling from Siliguri to Dhupguri had a head on collision with the small pick-up van, leading to death of all the three occupants of MUV car on spot.
Three others, the driver of the pick-up van, the helper and a passenger were seriously injured and taken to nearby hospital, he said.
The mishap caused disruption of vehicular transport on the arterial road for some time, police officer added.