The Border Security Force (BSF) recovered arms and grenade launcher from a house in Aizawl, the state capital of Mizoram.
It is suspected that the arms were dumped by Myanmarese rebels.
According to media reports, the BSF recovered the arms and ammunition from a house on Tuesday during a regular patrolling in an area within Aizawl.
The operation was carried by 61 Battalion.
According to a BSF statement, the arms recovered included six M-16 rifles, three AK-47, one SLR rifle and one G-3 rifle, a 9mm pistol, two claymore mines, and an under-barrel grenade launcher.
The BSF jawans also recovered Rs 1,19,100 cash from the house which is just 5 kilometre from the international border with Myanmar.
The BSF claimed that the arms and grenade launcher might have been dumped by the Arakan Liberation Army, a rebel group in the western state of Rakhine in Myanmar.
The Arakan Liberation Army (ALA) is currently in a ceasefire with the Myanmarese government.
The ALA rebels represent the Buddhist inhabitants of Rakhine state. They have been fighting for autonomy.
Mizoram, Assam, Tripura and Meghalaya, the four northeastern states share a 1,880-km border with Bangladesh, while Mizoram, Manipur, Nagaland, and Arunachal Pradesh have a 1,640-km unfenced border with Myanmar.
A few years back, the Assam Rifles seized 33 AK-47 rifles, a combat browning automatic rifle, a 5.56 automatic light machine gun, 49 loaded magazines and 809 rounds of ammunition from the outskirts of Aizawl.