Myanmar's flooding death toll rose to 74 as of Friday evening, according to a state media report on Sunday, after heavy rains triggered widespread floods across the war-torn country.

Search-and-rescue operations are ongoing, with at least 89 people missing as of Friday evening, the report said.

Adverse weather brought on by Typhoon Yagi, the strongest storm to hit Asia this year, has killed more than 260 people in Vietnam, Thailand and Laos, and floodwaters from swollen rivers have inundated cities in those countries.

The flooding in Myanmar began last Monday, and at least 19 people had been killed by Friday morning.

Myanmar has been in turmoil since a military coup in February 2021, and violence has engulfed large parts of the impoverished country.

The United Nations Office for the Co-ordination of Humanitarian Affairs (OCHA) said the storm's rains mainly affected the capital, Naypyidaw, as well as the Mandalay, Magway and Bago regions, along with eastern and southern Shan state, Mon, Kayah and Kayin states.

"Central Myanmar is currently the hardest hit, with numerous rivers and creeks flowing down from Shan hills," OCHA told Reuters via email.

Reports of more deaths and landslides have emerged, but gathering information has been challenging due to damaged infrastructure and downed phone and internet lines.

State media also reported that five dams, four pagodas and more than 65,000 houses were destroyed by the flooding.

About a third of Myanmar's 55 million people require humanitarian assistance, but many aid agencies, such as the International Committee of the Red Cross, cannot operate in many areas because of access restrictions and security risks.