The ultras who hailed from Ukhrul district of Manipur and in their 20s were arrested yesterday, an Assam Rifles statement said.
A 30-year-old Myanmarese national who was working as a guide of the militants was also nabbed.
The force seized three assault rifles, six magazines, 180 numbers of assorted ammunition and one Chinese hand grenade from the militants, the statement said.
The ultras and the recovered weapons were later handed over to Kakching Police Station, the statement informed.