During the joint operation of Assam Rifles, CRPF Cobra battalion and police, the four men - Parmeshwar Khaklary, Palwan Boro, Bishnu Boro and Ranjali Basumatary - were apprehended from the northern range of Sonitpur district, Superintendent of Police Sanjukta Parasar said.
One grenade, four rounds of ammunition and mobile phones along with SIM cards were recovered, she said.