The vehicle carrying the police personnel from Cooch Behar to Malda collided head-on with the truck on the Changrabandha-Mynaguri road at around 6.30 A M, official sources said.
Both the vehicles were travelling at high speed amid foggy weather when the mishap occurred, they said.
The driver of the truck is absconding while the injured policeman was admitted in a serious condition to the Jalpaiguri Civil Hospital.
The victims are Gopal Dey Sarcar and his colleague of the same name, Rajesh Sheikh (driver), Amind Kongar, Madan Chetri, Samiul Islam and Rezaul Islam.