Acting on a tip-off, police nabbed the trio travelling on a motorcycle near Society Chowk on National Highway 31 and seized two grenades, 15 detonators, two gelatin sticks and three cartridges of AK-47 rifles, they said.
The arrested youths have been identified as Suroj Das, Hemen Talukdar and Harshajit Pathak, while another managed to escape, sources added.