Clashes have rocked Myanmar's western Rakhine state since the Arakan Army (AA) attacked security forces in November, ending a ceasefire that had largely held since the military's 2021 coup.

Guterres is "alarmed by reports of ongoing air strikes by the military, including today in Minbya township that reportedly killed and injured many civilians," a spokesman for the UN chief said Monday.

Minbya township lies east of state capital Sittwe, which has been all but cut off by AA fighters in recent weeks.

The air strike hit the village of Thar Dar around 1:45 am on Monday, killing 10 men, four women and 10 children, one resident told AFP.

"There was no fighting in our village and they bombed us," he said, asking for anonymity for security reasons.

Another resident, also asking for anonymity, said 23 people had been killed in the blast and 18 wounded.

The recent conflict has displaced tens of thousands in Rakhine, where a 2017 military crackdown sent hundreds of thousands of Rohingya fleeing to neighbouring Bangladesh.

With most mobile networks down communication with the riverine region is extremely difficult.

Junta troops hold Sittwe but in recent weeks AA fighters have made gains in surrounding districts.

Fighting has also spilled over into neighbouring India and Bangladesh.

Last month, at least two people were killed in Bangladesh after mortar shells fired from Myanmar during clashes there landed across the border.

The AA is one of several armed ethnic minority groups in Myanmar's border regions, many of whom have battled the military since independence from Britain in 1948 over autonomy and control of lucrative resources.