At least 13 civilians were shot dead by Indian soldiers during an ambush carried out in error and subsequent protests over the incident in a remote north-eastern state.
One soldier was also killed in the violent clashes between protesters and troops on Saturday in Nagaland state’s Mon district, which borders Myanmar.
Authorities said six miners died after soldiers of the Assam Rifles regiment mistook them for armed rebels and fired at their vehicle as they returned home. The region has been in the grip of a decades-long armed separatist insurgency.
Two others were injured in the shooting late on Saturday, which caused deadly street clashes.
At least seven protesters and the soldier were killed during violence that lasted for hours, as locals attacked troops over the killing of the miners.
"So far the death toll remains at 13," Mon health officer Lolekhol, who uses one name, told The National.
Mr Lolekhol said at least 10 other civilians were undergoing treatment at the hospital for firearm injuries. The Indian army said an unknown number of soldiers were also injured in the violence.
The army said that it had opened an investigation into the killings and promised “appropriate action” against its troops “as per the course of the law”. It said the incident occurred when soldiers acting on a "credible intelligence" laid an ambush to trap insurgents operating in the area.
State chief minister Neiphiu Rio condemned the killings and appealed for peace in the region as the situation remains critical.
“The unfortunate incident leading to killing of civilians at Oting, Mon is highly condemnable. Condolences to the bereaved families and speedy recovery of those injured,” Mr Rio tweeted.
Nagaland is one of India’s eight remote north-eastern states, mostly inhabited by tribal communities, where scores of armed rebel groups have been fighting India's central government over demands ranging from self-governance to secession.
The region often records episodes of violence and allegations of human rights abuse by Indian troops and armed rebels.
Last month, an army colonel, his wife, their son, 8, and four soldiers were killed by armed militants after they ambushed their convoy in the neighbouring Manipur state.
