The United States has expressed concern about increased military operations in parts of Myanmar, including Chin state, where it said more than 100 homes and churches had been destroyed in the offensive.
Myanmar has been in turmoil since a Feb 1 coup and the United Nations and local media have recently reported a buildup of heavy weapons and troops, suggesting an imminent attack by the ruling military.
"We are also deeply concerned over the Burmese security forces’ intensification of military operations in various parts of the country," the US State Department said on Sunday.
It accused security forces of gross human rights violations which it said laid bare the regime's disregard for peoples' lives and welfare.
Witnesses, aid groups and local media have reported burning down of houses and an exodus of people from Thantlang town in Chin state.
Salai, a member of a local anti-junta militia, said the army fired artillery into the town on Oct 29, starting off a fire in some houses.
Soldiers then set fire to houses, Salai said, adding he could see from a hill overlooking the town.
"We saw the smoke and we knew that some of our homes were on fire. There was nothing that we could do about it, just to watch the burning," he told Reuters.
Drone footage the next day showed 164 houses and two churches were destroyed, he said. Reuters has not viewed the footage.
A spokesperson for the junta did not respond to a phone call for comment. The army has called the militias "terrorists" intent on destroying the country.
Since the coup, thousands of people have fled Chin state into neighbouring India.
A local elder in Thantlang, who manages camps of displaced people, said only one family was left in the town.
"The home is where our heart is. People here worry that the rest of the homes will be burned down by them. This is our biggest worry."
News portal DVB quoted Thantlang politician Salai Dokhar as saying blazes were ongoing and 270 homes had been torched.