Floods, landslides and other natural disasters triggered by downpours have left 90 people dead and 34 others missing in Vietnam's central region over the past two weeks.

At least 26 people have died after 46 days of heavy rains in South Korea, with the country's longest monsoon in seven years causing more flooding, landslides and evacuations on Saturday.

Heavy rains triggered flash floods and landslides that killed at least 40 people and displaced thousands in western Nepal, officials said on Saturday.

At least 21 people were killed in a series of landslides triggered by incessant rains in India's north-eastern state of Assam on Tuesday, officials said.

Tropical Storm Amanda triggered flash floods, landslides and power outages as it barrelled through El Salvador and Guatemala Sunday, killing 14 people, authorities said, warning of further heavy rain to come.

Rescuers worked by hand to clear debris from a landslide triggered by heavy rains in central Japan on Saturday, as the toll from the storms rose to 10 dead with a further three people reportedly missing.

Tens of thousands of rescuers were working through Sunday night to reach people feared trapped in Japan by landslides and floods caused by a powerful typhoon

Qatar Red Crescent Society (QRCS) has immediately responded to the devastating flash floods in southeastern and central Nepal.

Two people were killed in landslides and floods caused by tropical storm Bailu in the northern Philippines, local authorities said on Saturday.

At least 18 people were killed and another 15 to 20 were missing in landslides and other incidents on Sunday prompted by severe rainfall in India's mountainous northern states, officials said.

More than 350 people have now died as a result of flooding and landslides in South Asia brought on by heavy monsoon rains over the past few weeks, officials said Saturday.

The death toll in Nepal from flash floods and landslides in the past three days rose to 55 on Sunday, with dozens missing and injured, the government said.