Police said one of the three soldiers of the 12 Para Commandos of the Army injured in the battle at Lapa Lempong hilltop in Oting village was in critical condition.
Acting on intelligence inputs, a combined team of Para Commandos and Territorial Army ambushed a group of National Socialist Council of Nagaland-Khaplang (NSCN-K) and the United Liberation Front of Asom-Independent (ULFA-I) militants.
The militants had sneaked in from Myanmar into Nagaland's Mon district. Search operations were on to nab the fleeing militants.
Nagaland Police chief L.L. Doungel told IANS that Major David Manlum of Territorial Army was killed and three para commandos were injured in the fighting.
He said four militants, whose identities are yet to be identified, were also killed. "We are still waiting for a detailed report on the incident," Major Doungel said.
The mortal remains of Major David Manlum will be flown to Shillong for last rites.