The statements came after local media and residents said that soldiers seized 11 people from Dontaw village in Sagaing region following mine and bomb attacks on a military convoy on Tuesday.

Washington said it had received "credible and sickening reports that the Burmese military bound 11 villagers -- including children -- in northwest Burma and burned them alive," State Department spokesman Ned Price said on Thursday, using the country's former name.

Myanmar's junta, which seized power in a coup that deposed Aung San Suu Kyi's government 10 months ago, denied the claims.

It has been locked in a bloody stalemate with militias dotted around the country fighting to overturn the coup.

The state-backed Global New Light of Myanmar newspaper said Friday the reports were "fake news" and evidence of a "conspiracy by local and international connections".

A UN official told reporters in Geneva they were "appalled by the alarming escalation of grave human rights abuses in Myanmar."

"The country's human rights situation is deepening on an unprecedented scale, with serious violations reported daily," the spokesman for the Office of the High Commissioner for Human Rights (OHCHR) said.

- 'Completely unacceptable' -

Speaking to AFP on condition of anonymity, a resident said they saw "dead bodies lying with their hands tied, still smoking" after troops left Dontaw village.

A video posted on social media purported to show several badly charred bodies lying on the ground.

"It hurts us all... They don't even look human," says one voice in the clip that purports to show the remains.

AFP digital verification reporters found no evidence the clip had appeared online before Tuesday, though they were unable to identify where it had been filmed or whether it was authentic.

Meanwhile, the Democratic Voice of Burma outlet also reported troops had seized villagers who had been unable to flee following an attack on junta troops.

Sagaing region has seen regular clashes between junta troops and civilian militia.

Another Dontaw resident told AFP that the 11 had been "arrested while they were hiding" near a monastery on the west side of the village, and had been taken away by junta troops.

The Southeast Asian country has been in turmoil since the military seized power, with the economy in tatters and more than 1,300 people killed by security forces, according to a local monitoring group.

The OHCHR spokesman also condemned the junta after soldiers rammed a car into a peaceful protest in Yangon on Sunday, causing several casualties.

"These attacks are heinous... completely unacceptable, and disregard common values of humanity," it said.