Police yesterday arrested four members of a gang, who tried to snatch Tk 6 lakh from a fertiliser trader in Madhupur upazila, posing themselves as members of the Detective Branch (DB) of police. The arrestees are Saidur Rahman, 25, of Gazipur, Ali Hossain, 32, of Barisal, and Faruk Hossain, 30, and Jewel Miah, 25, of Pirojpur district. A gang of seven in the guise of DB men took fertilizer trader Anwar Hossain of Ashra village in Madhupur into a microbus at Kakraid area around 4:00pm, said Shahidul Islam, officer-in-charge (OC) of Madhupur Police Station. The criminals tied the trader and snatched Tk 6 lakh from him.