At least 27 people have been killed and more than 150,000 affected by flooding in Myanmar in recent days with the government declaring the four worst-hit areas in central and western Myanmar as "national disaster-affected regions".

Scores have also perished in India, Nepal, Pakistan and Vietnam following floods and landslides triggered by heavy seasonal rains. Rescue work in Myanmar has been hampered by continued downpours and the inaccessibility of many of the remote regions worst hit by the deluges.

The UN's Office for the Coordination of Humanitarian Affairs said today it had been informed by the Myanmar government's Relief and Resettlement Department that at least 156,000 people have been affected by the floods.

But that figure was likely to be "significantly higher" because many areas "have still not been reached or reported on by assessment teams," the agency warned. OCHA said the official death toll of 27 was also likely an underestimate.

"As further information becomes available, this figure is also expected to increase," the statement said.

The sheer extent of the flooding is testing the government's limited relief operations. An official at Myanmar's social welfare ministry who did not want to be named told AFP Saturday that all but one of the country's 14 provinces and regions were affected by flash floods with rescue workers "struggling to access flood-hit areas".

Myanmar is annually struck by monsoon rains that are a lifeline for farmers, but the rains and frequent powerful cyclones can also prove deadly, with landslides and flash floods a common occurrence. In May 2008 Cyclone Nargis devastated Myanmar's Irrawaddy Delta killing about 140,000 people. The then ruling junta's slow response to the disaster fuelled resentment against the isolated regime and sparked international criticism.

Three years later the army ceded control to a quasi-civilian reformist government and fresh elections are slated for November 8. The country's leaders have been keen to show flood relief is a top priority.

State media has run reports on President Thein Sein visiting victims in northwestern Sagaing region while powerful army chief General Min Aung Hlaing flew to flood-hit Rakhine. Seasonal monsoon rains have also brought death and destruction to other Asian nations.

In Pakistan, flooding has killed 81 people and affected almost 300,000 in the last two weeks. Flash floods in western India have killed 26 people while the Press Trust of India said at least 20 people died over the weekend in a landslide in Manipur state which borders Myanmar.

In Vietnam's Quang Ninh province 14 people have been killed in flooding while 36 people have perished in landslides in Nepal.

Latest News from World News Desk