Acting on a tip-off, police arrested the trio, who had robbed a couple early today, from the railway tracks near Ataliagaon while they were on they were on their way to board the Inter-City Mariani-Alipurduar Express enroute to Dimapur.
The police recovered a 3.2 mm pistol, three rounds of live ammunition, five mobile sets and several gadgets used for lifting cars, opening lockers, shutters and locks and doors.
The trio had tied a couple - Biren Borah and Niru Borah - at their residence in Pragati Nagar of Bongal Pukhuri under Jorhat Police Station and looted Rs 60,000 in cash and gold ornaments worth Rs 5 lakh.
The arrested members of the gang, based at Dimapur, have been identified as Sanjiv Bordoloi, Dulal Saikia and Subhash Dhar and search operations were on to apprehend the remaining four members of the gang, Parasar added.