Myanmar's military said on Wednesday it carried out a deadly attack on a village gathering organised by its insurgent opponents this week.
At least 50 people, including children, were killed in Tuesday's air strike in the Sagaing area in northwest Myanmar, according to media reports.
Myanmar has been in turmoil since a 2021 coup ended a decade of tentative reform that included rule by a civilian government led by Nobel Peace Prize laureate Aung San Suu Kyi.
Some opponents of military rule have taken up arms, in places joining ethnic minority insurgents, and the military has responded with air strikes and heavy weapons, including in civilian areas.
UN Secretary-General Antonio Guterres condemned the air attack in Sagaing and called for those responsible to be held accountable, his spokesperson said, adding that Guterres "reiterates his call for the military to end the campaign of violence against the Myanmar population throughout the country".
Junta spokesman Zaw Min Tun told military broadcast channel Myawaddy the attack on the ceremony held by the National Unity Government (NUG), a shadow administration, for their armed People's Defence Force was aimed at restoring peace and stability in the region.
"During that opening ceremony, we conducted the attack. PDF members were killed. They are the ones opposing the government of the country, the people of the country," said Zaw Min Tun.
"According to our ground information we hit the place of their weapons' storage and that exploded and people died due to that."
Referring to accusations of civilian casualties, he said "some people who were forced to support them probably died as well".
Zaw Min Tun said photographs showed some of those killed were in uniform and some in civilian clothes, accusing the PDF of falsely claiming civilian deaths when their forces were killed.
He also accused members of the PDF of committing "war crimes" and killing "monks, teachers and innocent residents" in the area who did not support the opposition.
Citing residents of the region, BBC Burmese, Radio Free Asia (RFA) Burmese, and the Irrawaddy news portal reported between 50 and 100 people, including civilians, had been killed in the attack by government forces.
Tuesday's incident is one of the deadliest in a string of air strikes. In October, a military jet attacked a concert, killing at least 50 civilians, singers and members of an ethnic minority insurgent force in Kachin State in the north.
Kyaw Zaw, a spokesman for the NUG, said it believed nearly 100 people were killed in the Tuesday attack when air force jets dropped bombs on villagers and military attack helicopters then followed up, calling it "another senseless, barbaric, brutal attack by the military".
The military denies accusations it has committed atrocities against civilians and says it is fighting "terrorists" determined to destabilise the country.
The military has ruled Myanmar for most of the past 60 years saying it is the only institution capable of holding the diverse country together.
Suu Kyi, 77, is serving 33 years in prison for various offences that she denied and her party has been disbanded.