An Australian tour group with two young boys, aged 11 and 14, and a 64-year-old woman are missing in the aftermath of Nepal’s devastating flash flooding that has killed at least 162 people.

Himalayan Glacier Adventures said 15 Aussies were on a 14-day hike when sudden floodwaters triggered by a glacier landslide smashed the region — with nine males and six females among them.

At least 34 Australians are among 400 missing tourists who were near the Himalayan border between Nepal and Tibet when a terrifying wall of mud and rock collapsed into a river on Wednesday.

Rescuers transport an elderly woman rescued from an old-age home following a flash flood in Trishuli Bazar, Nepal. Photo: AAP

The earth-shattering landslide sent a violent cascade of water downstream into towns and villages, wiping out homes, buildings and bridges and sweeping away people and cars.

Pictures are now emerging of the shocking aftermath, with survivors being dragged out of thick heavy mud which blankets the towns in northern Nepal.

Vast expanses that were once built-up areas of towns are now nothing but an empty canvas of silt.

Foreign Minister Penny Wong confirmed DFAT was urgently working to locate the Australians, and crisis personnel would be deployed.

However, she said communications in Nepal was difficult.

Damaged houses in the aftermath on the Trishuli River in Nepal’s Nuwakot district. Photo: AAP

The powerful flash floods in a border area of Nepal killed at least 162 people. Nepali ⁠police said 157 ‌bodies had been recovered so far.

The Australian tourists were hiking from Kathmandu to Mount Kailash but lost contact with the tour company after the landslide on Wednesday morning around 8.30am local time.

“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,” the US-based Himalayan Glacier team said in a statement.

Hundreds of international tourists, workers and others are missing, including 47 from the United States, 34 from Australia, 33 from the United Kingdom and 24 from Canada.

Houses, roads and power projects were swept away in Nepal, while officials in Tibet said they feared “major casualties” after a mudslide hit a border land crossing in the county of Gyirong.

As darkness fell, authorities continued the grim task of recovering and ‌trying to identify bodies.

The debris-choked banks of the Trishuli River, Nepal. Photo: AAP

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.

“We are liaising with local authorities as well as tour operators. We stand ready to provide consular assistance.”

Albanese expressed his “deepest sympathies” to those affected by the flooding.

A suspension bridge in Nuwakot, Nepal. Photo: AAP

Wong said the loss of life and destruction caused by flash flooding was devastating, Foreign Minister Penny Wong said.

“Our thoughts are with the loved ones of those killed or missing and all affected by this disaster,” she said in a statement on Thursday morning.

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

“Our thoughts are with all those affected by this disaster. 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.

-with AAP