Survivors told the BBC they have collected at least 80 bodies, but expect the toll to rise further. The United Nations has condemned the attack, which targeted a village in the north-western Sagaing region. The military has increasingly used air strikes against their opponents since seizing power in February 2021. 

The spokesman for the military junta, General Zaw Min Tun, told state television, "yes, we launched the air strike". He said they had chosen to attack Pa Zi Gyi because the village was holding a ceremony to mark the opening of an office for their local volunteer defence force.

These anti-coup militias, known as People's Defence Forces or PDFS, are waging an armed campaign against the military in various parts of Myanmar. Communities in Sagaing have put up some of the strongest opposition to military rule.

One villager in Pa Zi Gyi told the BBC that a military jet had flown over at about 07:00 local time (01:30 BST) on Tuesday and dropped a bomb directly onto the hall where community leaders were meeting, followed by a helicopter gunship which attacked the village for 20 minutes. Later, witnesses said, the aircraft returned and opened fire on those trying to collect the dead.

The village had been packed with people from nearby communities who were attending the ceremony.

After the airstrike, residents uploaded video showing scenes of appalling carnage, with dismembered bodies lying on the ground and several buildings on fire. "Please call out if you are still alive, we are coming to help you," they can he heard shouting as they walked through Pa Zi Gyi looking for victims of the attack.

They said that they tried to count the bodies, but that this was difficult because so many were in pieces, scattered among shredded clothing and burned motorbikes.

"Despite clear legal obligations for the military to protect civilians in the conduct of hostilities, there has been blatant disregard for the related rules of international law," the UN High Commissioner for Human Rights, Volker Turk, said.

"There are reasonable grounds to believe that the military and its affiliated militias are responsible for an extremely broad range of human rights violations and abuses since 1 February 2021, some of which may constitute crimes against humanity and war crimes."

Thousands have been killed in the civil war, with an additional 1.4 million displaced. Nearly a third of the country's population is also in need of humanitarian aid, according to the United Nations.

There were at least 600 air attacks by the military between February 2021 and January 2023, according to a BBC analysis of data from the conflict-monitoring group Acled (Armed Conflict Location and Event Data Project). The junta has been increasingly relying on its Russian and Chinese aircraft to bomb opposition-controlled villages, inflicting much higher casualties among non-combatants.

The exiled National Unity Government, which was formed after the coup, says that these attacks killed 155 civilians between October 2021 and September 2022.

In October, at least 50 people were killed after air force jets dropped three bombs on a concert organised by an ethnic insurgent group in Kachin state. In the previous month, an airstrike on a school in the village of Let Yet Kone in central Myanmar killed at least five children and injured several others.

If the death toll at Pa Zi Gyi is confirmed, it will be one of the deadliest single incidents so far in the civil war.

Last month, Gen Min Aung Hlaing, the head of the military government, said the regime would deal decisively with what he described as "acts of terror" by armed resistance groups.