Myanmar has been reeling from civil war since the military seized power in a 2021 coup, prompting pro-democracy rebels to take up arms and ally with ethnic armed groups against the junta.

Hundreds of people were gathered in central Myanmar's Chaung U township for the Thadingyut full moon festival on Monday evening when the military dropped bombs on the crowd, according to a member of the committee that organized the event.

The woman, who requested anonymity for security reasons, said people were gathering for the festival and an anti-junta demonstration at around 7:00 pm when the bombs killed more than 40 people and wounded about 80 others.

"The committee alerted people and one-third of the crowd managed to flee," she told AFP. "But immediately, one motor-powered paraglider flew right over the crowd", dropping two bombs on the center of the gathering.

"Children were completely torn apart," said the woman, who was not at the scene but attended funerals on Tuesday.

When another motorized paraglider flying overhead left the area, she said people rushed to help the wounded.

"As of this morning, we were still collecting body parts from the ground -- pieces of flesh, limbs, parts of bodies that were blown apart," she added.

A resident of Chaung U who attended the event Monday confirmed the estimated toll, saying people attempted to run when they realized the paramotor was flying overhead.

"While I was saying to people 'please don't run', the paramotor dropped two bombs," he told AFP, speaking on condition of anonymity.

"Two of my comrades were killed just in front of me. There were even more who died in front of me."

He said he attended funerals on Tuesday for nine friends who were killed.

A local media outlet also said 40 people were killed in the attack.

A junta spokesperson could not immediately be reached for comment late Tuesday.

Human rights watchdog Amnesty International said in a statement that the nighttime attack "should serve as a gruesome wake-up call that civilians in Myanmar need urgent protection."

The attack showed the military was "intensifying an already brutal campaign against pockets of resistance," the London-based organization said.

"The international community may have forgotten about the conflict in Myanmar, but the Myanmar military is taking advantage of reduced scrutiny to carry out war crimes with impunity," said Joe Freeman, Amnesty's Myanmar researcher. 

He called on the Association of Southeast Asian Nations bloc to increase pressure on the Myanmar junta as ASEAN officials prepare for a meeting later this month.

The junta has touted elections beginning on December 28 as a path to reconciliation.

But a UN expert has dismissed the vote as a "fraud" to disguise continuing military rule, and rebels have vowed to block it.

The military is now besieging rebel enclaves, aiming to expand territorial control ahead of the polls.