A senior UN official called on Myanmar authorities to investigate the reported killing of at least 35 civilians that opposition activists blamed on government soldiers, saying he was “horrified” at the violence.

The ruling military has not commented on the killings near Mo So village in Kayah state on Friday and junta spokesman Zaw Min Tun could not be reached by phone for comment.

State media reported on Sunday that soldiers had fired on and killed an unspecified number of “terrorists with weapons” from forces fighting the military government. State media did not say anything about civilians.

UN under-secretary-general for humanitarian affairs and emergency relief coordinator Martin Griffiths said reports of the killing of civilians, including at least one child, were credible.

“I am horrified by reports of an attack against civilians... I condemn this grievous incident and all attacks against civilians throughout the country, which are prohibited under international humanitarian law,” he said.

Griffiths called for “a thorough and transparent” investigation so the perpetrators could be brought to justice.

Residents and a human rights group working in the area said soldiers had killed the civilians. Photographs posted by the rights group showed charred bodies, some in the back of a burned-out truck.

Myanmar has been in turmoil since the military on February 1 overthrew the elected government of Nobel Prize laureate Aung San Suu Kyi.

Some opponents of the military have taken up arms, some linking up with ethnic minority guerrillas who have for years been fighting the government for self-determination in various parts of the country, including Kayah state in the east.