A 13-year-old British girl and 32 other people from the UK are feared missing, and more than 150 people were killed when a huge wall of mud and rock collapsed into a river on the border of Nepal and Tibet, sending flash floods through villages. Rescuers in Nepal have recovered 157 bodies, while hundreds of people, including two Irish nationals, are also still unaccounted for.Houses, roads, a metal bridge and power projects were swept away in in Nepal’s Rasuwa region, while witnesses said the waters engulfed entire villages. Trees and vehicles were submerged or buried in mudslides.“There is devastation everywhere ‌we look,” said Tula Bahadur BK, a health worker. “The settlements next to the river have been completely swept away. Five of my own relatives are missing.” Officials in Tibet said they feared “major casualties”. Climate experts say an avalanche from a glacier is likely to have caused the disaster.Security footage from the Chinese side of the Nepal-Tibet border showed people fleeing before a torrent of rock, mud and water engulfed the area, destroying buildings and vehicles and ⁠taking lives.Buildings were submerged in a sea of mud in Nepal (Reuters)One man being treated in hospital said: “It was a huge gush of mud coming straight towards us. As it got closer, it kept rising higher and higher. When I saw it enter our home, I tried to grab my wife’s hand and take her to the terrace. But she was swept away by the mud.Keshav Prasad Baral, 68, said: “Four or five hours later, a ⁠helicopter came to rescue me. My wife is still somewhere beneath the mud. She’s gone.”With the deluge of muddy water sweeping down from an estimated 6,560ft above ​sea level, flood ⁠alerts were issued in the populous northern Indian states of Uttar Pradesh and Bihar, which border Nepal. About 5,000 people in Bihar were forced to flee and up to 7,000 more were set to leave.At least 157 people were killed in the floods at the border between China and Nepal (AFP/Getty)The office of Nepal’s prime minister said 484 tourists were missing, of whom 391 were foreigners and 93 Nepalis. More than 40 people were being treated in hospital. A tourism board spokesperson said 133 people were from India on pilgrimage to Mount Kailash in Tibet, a sacred site for Hindus, which attracts hundreds of pilgrims at this time of year. Also missing were 47 from the United States, 34 from Australia, 33 from Britain and 24 from Canada, he said. Travel logs show the ages of the missing British citizens range between 13 and 65.Houses lie partially submerged in muddy water along a riverside in Nepal (AFP/Getty)Alpine Eco Trek, which runs expeditions in Nepal, said four of its Nepalese tour guides – aged 38, 35, 45, and 29 – were among the missing.Kumar Adhikari, the company manager, said he was fielding thousands of missed calls from families back in the UK which he has been “slowly responding to”. The Nepal Tourism Board said its staff and tourist police were “working to verify the whereabouts and safety status of tourists and travellers who were in or travelling through the affected areas”.Police were recording names of the missing using phone flashlights for light because the electricity was cut off. South Korea said eight of its nationals working on a ‌hydropower plant were missing and 10 others were stranded.Members of the Nepali Army carry a survivor who was being airlifted (Reuters)The Nepalese government said it had asked both India and China to help with the rescues, and officials warned residents to stay away from the banks of the Bhotekoshi, Trishuli and Narayani rivers.China has deployed ⁠at least 574 rescuers to the land crossing but the flood ⁠sediment is posing a challenge. The country’s state broadcaster said three people were killed and 265 others were missing in Gyirong, the first casualty figures provided for that side of the border. Other countries have also offered to help.In a joint statement with Australia, the EU, Finland, France, Norway and Switzerland, the UK embassy in Nepal said: “We are deeply saddened by the devastating flooding in Rasuwa and Nuwakot districts and surrounding areas.“Our thoughts are with all those affected by this disaster. We express our solidarity with the people of Nepal during this difficult time.”Prime minister Andy Burnham said the government would do everything it could to support Britons in Nepal amid “devastating” scenes.“My thoughts are with all those affected, including the families and loved ones of British nationals missing in this tragedy,” he said.“We will do everything we can to support British nationals impacted in the region and are in touch with the relevant authorities to offer support.”Climate experts at the Kathmandu-based International Centre for Integrated Mountain Development said an avalanche from a glacier was likely to have caused the flash flood.The Lhende Khola River, a tributary of the Bhotekoshi, had maximum flooding on Wednesday, they said."The Lhende Khola has flooded twice in 14 months, this time triggered by an ice rock avalanche from a glacier on the Nepal side that blocked the river and released a sudden surge downstream," said Saswata Sanyal, a disaster risk reduction specialist at the climate research group.He noted the importance of early warnings in "a warming Himalaya".The region suffered similar flash floods in August last year, when a glacial lake in Tibet overflowed because of high temperatures. Nine people were killed, and critical infrastructure, including a bridge connecting Nepal and China, was damaged.The Himalayan region, which spans several countries including India, is especially vulnerable to heavy rains, floods and landslides because of warming due to human-caused climate change. Research shows that extreme weather events, including heatwaves, rains and melting glaciers, have become more frequent.Researchers in Kathmandu found earlier this year that glaciers across the Hindu Kush Himalaya region are melting at an accelerating rate, with ice loss rates doubling since 2000, primarily due to rising global temperatures and climate change.