An NHS psychiatrist is among 33 British nationals missing in Nepal following a catastrophic flash flood and mudslide that swept through the region on Wednesday. The disaster, triggered by a glacier collapse, has killed at least 538 people and left over 1,500 missing, with rescue efforts hampered by the remote and devastated terrain.

Desperate families of those who were in the mountainous region have begun arriving in Nepal to search for their loved ones. Among them is Manjula Atmakur, wife of 54-year-old Pravin Atmakur, an NHS consultant psychiatrist who was leading a group of 77 pilgrims to Mount Kailash in Tibet when the floods struck.

Mrs. Atmakur last spoke to her husband on August 15 and believes he was returning from Tibet into Nepal when the disaster occurred around 9 a.m. on Wednesday. She arrived in Kathmandu on Friday and has sought help from the British embassy. "I am emotionally broken. I don't know how my husband is. In which situation. I want him back alive," she told The Telegraph in Nepal.

A millionaire family of four from Surrey, including former Mrs. India UK Surabhi Sahu, 44, her husband Santosh, 46, and their children Spandan, 18, and Syna, 13, are also among the missing Britons. The family had been on an adventure trek across the Nepal-China border. They were last heard from as they crossed the frontier from Nepal into Tibet, around the time the torrent of ice, mud, and rocks engulfed the Gyirong border crossing. CCTV footage captured people running for their lives as the disaster unfolded.

Another missing pair are Nelly Chhetri, 18, and her mother Yashika Basnet, 56, an NHS worker. They had joined a tour group and have not been heard from since. Their family has reported receiving no contact from the UK Foreign Office.

Samitra Sapkota, 25, the wife of British man Pramod Poudel, who runs a Nepalese street food company in Sussex, is also unaccounted for. Mr. Poudel last spoke to his wife, who was in Sole village in the Nuwakot district, on Wednesday morning, and has since seen images of the devastation where his family lived. His mother, brother, and uncle are also missing, though his father has been found alive.

Sunil Amin described the "horrible, horrible feeling" of repeatedly trying to contact his wife, Hema Amin, 63, who was on a pilgrimage with her sister. Sarada Simkhada, 55, a senior nurse from Dartford, was also on a pilgrimage to Mount Kailash and was last in contact when she was staying at the Kailash Hotel in Timure on the Nepal-China border. Roshan Panday, owner of Fishtail Tours and Travels Group, reported that none of his tour group of 27, which included Briton Leena Bector, 53, from Slough, were answering their phones. Bipin Patel, 66, and Mala Patel, 60, are also reported missing.

Foreign Office minister Stephen Doughty confirmed that the number of 33 Britons missing is the current information from the Nepal government but acknowledged that the figures may fluctuate due to the complex situation in remote areas. He stated that UK teams are in close contact with families and providing support.

The flooding was caused by a glacier collapse that sent a massive volume of water and debris surging downstream. Scientists are analyzing satellite and ground-level data to understand the precise sequence of events. Preliminary investigations suggest a large chunk of a glacier broke off, temporarily damming a river before releasing its water with devastating force. The US Geological Survey reported a magnitude 5.2 glacier collapse event.

Authorities in Nepal and China have warned of further flooding from a newly formed lake upstream that has begun overflowing, urging residents in potentially affected areas to move to higher ground. Rescue operations, which were temporarily halted due to this new risk, have resumed as Chinese authorities deemed the situation manageable.