Detectives in Khulna's Terokhada Upazila came under an attack during an anti-drug drive late on Wednesday, which left four injured and prompted the detention of three individuals in this connection.
The injured are the district Detective Branch ASI Moinuddin and constables Tabibur, Sohel and Shamim.
Meanwhile, those held over the attack are Abu Taher, Sohel Molla and Mofizul.
Khulna DB Officer-in-Charge (OC) Nurul Islam Badol said ASI Moinuddin has been admitted to Khulna Medical College Hospital.
Sources say that acting on a tip-off, a detective team conducted the operation in Amtala village at 9:30pm.
Suspected drug traders attacked them during the raid, injuring four.