The mishap took place last night when the policemen were alighting from their jeep at a checkpoint near Adarsh Nagar police station and a speeding truck hit the vehicle from behind, police said.
Constables Babu Ram and Laxmi Narayan, aged around 40 years, were killed on the spot while Niranjan, Hemant and Dhanpal got serious injuries.
The injured were rushed to a hospital, police said, adding that driver of the truck fled after the accident.