Myanmar's ruling junta has confirmed that it carried out an air strike on a village in which dozens of people were reported killed, drawing condemnation from the United Nations and Western nations.

UN rights chief Volker Turk said he was "horrified" by the deadly air strike, with the global body calling for those responsible to be brought to justice.

The death toll from the early Tuesday morning strike on the remote Kanbalu township in the central Sagaing region remains unclear.

At least 50 fatalities and dozens of injuries were reported by multiple news outlets.

The junta confirmed late on Tuesday night that the strike had taken place, but did not say how many were killed.

"There was (a People's Defence Force) office opening ceremony... (Tuesday) morning about 8 am at Pazi Gyi village," said spokesman Zaw Min Tun, referring to the armed anti-junta groups that have sprung up across the country since its elected government was toppled in a 2021 military coup.

Some of the dead, he added, were anti-coup fighters in uniform, though "there could be some people with civilian clothes".

The spokesman went on to blame mines planted by the People's Defence Force for some of the deaths.

The United Nations, while not confirming a toll, said several civilians were killed, with Turk accusing Myanmar's military of once again disregarding "clear legal obligations... to protect civilians in the conduct of hostilities".

Myanmar's National Unity Government, a shadow body dominated by former lawmakers from ousted civilian leader Aung San Suu Kyi's party, called the strike a "heinous act".

"We... share the great pain felt by the families affected by this tragedy," it said in a statement. (AFP)