Army jawan Gautam Lal who was killed in the rioting that followed the firing on civilians in Nagaland's Mon district was from Uttarakhand's Tehri district.
"We have received information about Lal being martyred in Nagaland," Sub-District Magistrate, Kirtinagar, Sonia Pant said.
A resident of Nauli village in Tehri, Gautam Lal was serving as a paratrooper in the 21 Battalion of Parachute Regiment.
The youngest of five brothers, he had joined the Army in 2018.
Gautam Lal's father Ramesh Lal and brother Suresh said they received information from the Army about his being injured on Sunday.
Six civilians were killed when army personnel mistook coal mine workers returning home in a pick-up van on Saturday evening to be insurgents belonging to the Yung Aung faction of the banned outfit NSCN(K) in Nagaland's Mon district.
As workers failed to reach their homes, local youth and villagers went in search of them and surrounded army vehicles. In the ensuing melee, one soldier was killed and army vehicles burnt down. Soldiers who fired in self-defence killed another seven civilians.
Rioting spilled over into Sunday afternoon when angry mobs vandalised the offices of the Konyak Union and an Assam Rifles camp in the area, setting fire to parts of the camp, according to police.
At least one more person was killed, as security forces fired back at attackers.