One of Myanmar's most powerful rebel groups on Monday said it had shot down a military helicopter, after returning fire following air strikes.
Kachin Independence Army representative Naw Bu said the helicopter was shot down at around 10.20am near the town of Moemauk, in the northern state of Kachin.
"The military council launched air strikes in that area from around 8am or 9am this morning using jet fighters and also fired shots using a helicopter, so we shot back at them," he said by telephone.
He declined to say what weapons were used.
News portals reported on the incident, publishing footage seemingly showing a helicopter trailing smoke as it falls to earth.
The UN estimates that tens of thousands of civilians have fled their homes as a result of the fighting between the military and ethnic minority insurgents in remote northern and eastern frontier regions.
The conflict intensified after Myanmar's generals seized power on February 1, ousting the elected government led by Aung San Suu Kyi.
A resident in the area, who declined to be named, said by telephone that four people had died in hospital after artillery shells hit a monastery in the village.
These reports could not be independently verified.
The Myanmar military did not respond to a request for comment.
Myanmar has been in turmoil since the coup, with protests almost daily against military rule across the country.
On Sunday, Myanmar security forces opened fire on some of the biggest protests in days, killing eight people, media reported.
The protests, after a spell of dwindling crowds and what appeared to be more restraint by the security forces, were co-ordinated with demonstrations in Myanmar communities around the world to mark what organisers called "the global Myanmar spring revolution".
The Assistance Association for Political Prisoners advocacy group says security forces have killed at least 765 protesters since the coup.
The military said it had to seize power because its complaints of fraud in a November election won by Ms Suu Kyi's party were not addressed by an election commission that deemed the vote fair.
Ms Suu Kyi, 75, has been detained since the coup, along with many other members of her party.