Already struggling with a third Covid wave in a health crisis worsened by conflict resulting from a coup, floods have submerged southern Myanmar and hampered efforts of front-line workers and aid groups.

Myanmar residents say rain and flooding were exacerbating the situation.

Incessant rains battered the southern states of Kayin, Mon and Tanintharyi region, affecting as many as 3,000 people.

More than 100 in Kayin's Hlaingbwe were evacuated. No deaths have been reported, Radio Free Asia said.

"It's been raining heavily. Cars and motorcycles are useless now. Houses that are level with the roads are all flooded," An Nu, a resident of Mawlamyine's Shwedaung, said.

"Daily wage earners living hand to mouth are in big trouble. They now must rely on donations from well-wishers," Nu added.

Some 500 residential areas along the country's border with Thailand have been affected, the Karen Information Center media group said.

"Hundreds of houses are submerged and only their roofs can be seen," the Bangkok Post quoted Pyae Sone, a social worker in Kayin State, as saying.

Medical workers trundled bedridden patients, still hooked up to oxygen tanks, over murky floodwaters in the Kayin town of Myawaddy, Facebook photos shared by the KIC news group showed.

Cases of the virus in Myanmar have increased since June, with 4,631 infections and 396 fatalities reported Tuesday.

But the toll is far higher, according to medics and funeral services.

Efforts to contain the spread of the disease in Myanmar were dealt a serious blow when the country's military seized power Feb. 1.

Angered by doctors' support for anti-junta demonstrations, Myanmar's military has also arrested several doctors treating virus patients independently, the Bangkok-based Assistance Association for Political Prisoners said.

"This flooding has totally exacerbated our problems," Aung Naing Oo, a doctor and a politician from Chaungzon township, said in the Radio Free Asia report.