Boys among Australians missing in Nepal flood disaster

Department of Foreign Affairs and Trade personnel, including crisis response experts, are being deployed to the devastated region, where at least 162 people have been killed and hundreds more are missing.

''I would anticipate that support will be needed,'' Senator Wong told reporters.

''If you look at the footage and the destruction, we know this is a country that may not have the resources that will be needed to deal with the recovery by themselves.''

The government is working to confirm if there are any other Australians missing in the region.

US-based travel company Himalayan Glacier Adventures confirmed 15 Australians, including the two boys aged 11 and 14, were on a tour when floods swept through the region, with fears growing for their safety.

Founder and chief executive Sagar Pandey told AAP the group lost contact after the landslide on Wednesday about 8.30am local time.

Nine males and six females are among the Australians missing with the group.

"The flooding has been severe and has caused significant disruption in the affected area," the Himalayan Glacier team said in a statement.

"Unfortunately, due to damage to mobile networks and electricity infrastructure, communication remains extremely difficult, and we have not yet been able to establish contact with anyone there."

Alpine Kailash Trek, a separate company, confirmed its customers were all safe in Saga, Tibet, including four Australians.

Officials at Nepal's tourism ministry told media outlets that 340 foreigners were among more than 400 tourists missing after the disaster.

Prime Minister Anthony Albanese urged Australians in the affected area to follow the advice of local authorities.

"We are aware of a number of Australians in the area and Australian officials are urgently working to confirm their welfare," he said in a statement.

A minute's silence was held before play at a T20 match in Darwin on Thursday as the Nepal cricket team, visiting Australia, paid tribute to those affected.

Smartraveller has updated its travel advice, urging people to exercise a high degree of caution due to major flash flooding and a mudslide that have caused significant damage to transport networks and infrastructure. 

International Nepal Fellowship Australia chief executive Richard Reeve, whose organisation works with people facing poverty in regional areas in the country, described the scenes as deeply distressing. 

"Nepal is home to many natural disasters. The monsoon rains are so heavy and so powerful they wipe out roads and bridges every year. But the images on the news, I've never seen rivers flow that fast with so much destruction," Mr Reeve said.

"The terrain is very steep. People had no chance."

The Rasuwa district, near the Tibet the border, will be extremely difficult to access due to the amount of damage, Mr Reeve said. 

"Road access has been wiped out, so we saw the bridges go and the roads go, that means trucks full of supplies and relief efforts just won't be able to get in," he said.

"It really is limited to helicopters, and there's not as many helicopters in Nepal as there are in Australia."

Opposition Leader Angus Taylor backed calls to follow local advice.

"Our thoughts are with all those affected by the devastating flooding in Nepal and Tibet, including the families who have lost loved ones and those still waiting for news," he said.

Australian Ambassador to Nepal Simon Ernst released a statement together with representatives from the embassies of the United Kingdom, France, Finland, Norway and Switzerland.

"We express our solidarity with the people of Nepal during this difficult time," they said.

Australians in need of urgent help should contact the Department of Foreign Affairs and Trade's 24- hour consular emergency centre.