A devastating flash flood has swept through parts of the Nepal–Tibet border region, leaving more than 400 people unaccounted for and at least 160 people dead, according to reports.

The disaster struck suddenly in the Himalayan region, sending huge volumes of water, mud and debris through communities along major river systems. Nepalese authorities have reported that 403 people remain missing, including hundreds of foreign nationals. Among those unaccounted for are 34 Australians, while people from India, the United States, Britain and Canada are also believed to be missing.

Many of the foreign travellers were reportedly making their way towards Mount Kailash in Tibet, a major pilgrimage destination for Hindus. At the same time, dozens of Nepali citizens were trekking in the Gosaikunda Lake area when the disaster occurred.

The scale and speed of the flooding have made rescue operations extremely challenging. Reports indicate that water levels in the Trishuli River rose by as much as nine metres in just 30 minutes, giving people little time to escape.

The flooding is believed to have been triggered by a combination of geological events, including a 4.4-magnitude earthquake and an avalanche or ice-rock avalanche that caused a sudden surge of water downstream.

Emergency teams are continuing search-and-rescue operations, although heavy mud and unstable conditions are hampering access. Nepal has sought assistance from neighbouring India and China, while Chinese authorities are also conducting rescue efforts on the Tibetan side of the border.

The tragedy has once again highlighted the vulnerability of communities across the Himalayas, where rapidly changing weather patterns, melting glaciers, floods and landslides are increasing disaster risks.