Deadly flash floods strike Nepal and Tibet, leaving hundreds dead and missing

Tens of thousands of emergency service workers in Nepal are wading through debris in search of life as survivors anxiously wait for news of missing loved ones.

The deadly flash floods that struck villages bordering Nepal and Tibet have killed at least 469 people, and thousands are still missing.

At least 39 Australians were missing, with nine people being publicly identified.

Foreign Minister Penny Wong said there was an "unfortunate possibility" the number of missing Australians could rise.

"It's a very difficult situation, it's a remote location," she told RN Breakfast.

"We are urgently working to identify how many Australians are, and have been, in the region and to confirm the welfare of any Australians who are not accounted for."

Among those in Nepal praying for the return of those missing was 33-year-old Shova Shrestha.

She has spent more than a day waiting to hear about her husband Rajan Shrestha's whereabouts.

When Ms Shrestha first tried calling his phone after the floods, it rang, but now it goes silent.

Since then, she has begun nervously watching every helicopter that has landed in Bidur, the capital of Nuwakot district.

Thousands of children affected by floods

At least 17,000 children in Nepal have been impacted by the flash floods, according to the United Nation's children agency.

UNICEF estimates about 10,000 school-aged children will need urgent support to continue their education as 18 schools have been destroyed and an additional 20 have sustained damage.

The agency's representative to Nepal, Alice Akunga, said children in Nepal's districts of Rasuwa and Dhading saw their lives washed away.

"Children who have survived the floods now face heightened risks of disease, malnutrition, violence and exploitation."

The federal government said Australia would provide $5 million in aid for communities affected by the floods in Nepal and Tibet.

The funds will be allocated to Australian not-for-profits and the United Nations' World Food Programme.

"We're also providing humanitarian assistance including food, emergency shelter and medical support," Prime Minister Anthony Albanese said.

"Our thoughts are with the loved ones of those affected as we urgently work to confirm the welfare of missing Australians."

Hundreds of foreign nationals missing

Among the 910 people missing in Nepal there are 517 foreign nationals from more than two dozen countries.

So far, these include:

178 people from India

90 from the United States

33 from Britain

25 from Canada

9 from Singapore

8 from Germany

5 from New Zealand

There were also almost 100 Chinese nationals among the missing in Nepal, according to China's foreign ministry.

Across the Tibetan border, China said 558 people including 260 foreigners were missing.

The United Nations said the Nepali government had more than 30,000 security personnel on its search and rescue operation.

It said the government's relief fund had secured $US229 million ($318 million) in funding commitments from the World Bank, India, China and the US.

Survivor says 'everyone is gone'

The tens of thousands of first responders used heavy machinery to dig through the mud and debris, with survivors being flown out by helicopter.

There have been more than 100 rescued by helicopter, according to the Nepali army.

Digby Tamang was one of those survivors.

His village Rasuwa was one of the hardest hit by the deluge.

He was flown to safety along with three people to an army camp in Nuwakot.

Mr Tamang was full of grief, saying he had nothing left.

"I have no one left waiting for me. Everything and everyone is gone. The end."