Dima Hasao, Nov 06 (ANI): Four militants were killed in two separate encounters with paramilitary Assam Rifles and the police in Dima Hasao district of Assam on Thursday. Huge cache of arms and ammunition was recovered from the militants. According to reports, the Assam Rifles had launched an operation near Robi Basti village, and indulged in a gun battle in which three militants were killed. Two AK series rifles, 73 rounds of ammunition and other war-like stores were recovered from the militants. The militants belonged to National Socialist Council of Nagalim - Isak- Muivah (NSCN-IM) rebel group. Meanwhile, another operation was conducted near Kopilo village, a day before, on the junction of Assam, Nagaland and Manipur, an area frequented by NSCN (IM) insurgents for their transit into the state, said sources. In the encounter an ultra was killed and one AK-47 rifle, one Lathod rifle, one hand grenade and over 100 rounds of ammunition were recovered from him.