The violent photos circulated online show the remains of bodies on burnt-out truckbeds near Mo So village of Hpruso town in eastern Myanmar.
More than 30 people, including women and children, have been killed and their bodies burnt in Myanmar's conflict-torn Kayah state.
Karenni Human Rights Group said they found the burnt bodies of internally displaced people, including elders, women and children killed by the military that rules Myanmar, near Mo So village of Hpruso town on Saturday.
"We strongly denounce the inhumane and brutal killing which violates human rights," the group said in a Facebook post.
The Myanmar military said it had shot and killed an unspecified number of "terrorists with weapons" from the opposition armed forces in the village, state media said.
The people were in seven vehicles and did not stop for the military, it said.
Photos shared by the human rights group and local media showed the charred remains of bodies on burnt-out truckbeds.
Resistance against junta
The Karenni National Defence Force, one of the largest of several civilian militias opposing the junta that led a Feb. 1 coup, said the dead were not their members but civilians seeking refuge from the conflict.
Myanmar has been in turmoil since the military overthrew the elected government of Nobel Prize laureate Aung San Suu Kyi almost 11 months ago, claiming fraud in a November election that her party had won.
International observers have said the ballot was fair.
Civilians enraged by the coup and subsequent crackdown on protesters have been taking up arms.
Many local resistance forces have sprung up across the country.