The injured cops are Sub Inspector Khokon (36), constables Enamul Haque (42), Abdul Momim (35) and Jamal (28).
Thakurgaon DB Police OC Rafiqul Islam said on the basis of secret information, police was informed that a group of robbers were taking preparations to commit robbery on the Thakurgaon-Dinajpur highway.
A joint team of Detective Branch (DB) police conducted a raid there. Sensing the presence of policemen, the robbers fired at them, forcing the policemen to back fire that triggered a gunfight. Later, an injured robber was rescued from the spot. When he was taken to Thakurgaon Sadar Hospital, the doctors declared him dead.
The injured policemen have been admitted to the hospital.
The OC also said police recovered some native weapons from the spot.