Officials said the three were apprehended after a special operation was conducted by the police few days back.
Superintendent of Police (Roing) S K Kain said they have apprehended Dagar Peme (30), Obang Lgo (36) and Bobel Lego (32) after an operation was conducted in the Kalapani area of Dambuk in the said district.
A senior officer said the forces recovered an automatic rifle, a loaded magazine, 25 bullets of AK series assault rifle from the "underground extortionists of the NSCN (K)".