Four AK-47 assault rifles, two AK-56 rifles, three G-3 rifles, one light machine gun, one Mark-4 rifle, 1,195 rounds of ammunition and 21 spare magazines were seized last night, a police official said.
Three persons, suspected to be Myanmarese nationals who smuggled the arms from Myanmar via the international border were arrested, he said.
The police suspected that the weapons were to be handed over to a Bangladesh-based Chakma insurgent group called the United People's Democratic Front, a breakaway group of the Shanti Bahini.
The joint operation was conducted by the Mizoram Police and 14 battalion Assam Rifles.