Nepal’s foreign minister Shishir Khanal said the flash flood was caused by an earthquake. “An earthquake occurred at 8:37 a.m. today, and due to it, a large landslide occurred, blocking the river, which appears to have caused the flood,” Khanal said during a meeting at the House of Representatives.

The United States Geological Survey, which records earthquakes worldwide, registered a 4.4-magnitude earthquake in the region at the same time as the one referenced by Khanal.

Initial reports from the affected areas and the National Disaster Risk Reduction and Management Authority said the swollen river swept many settlements across the 60-km road from Xylong in Tibet, China, down to Rasuwa, Nuwakot (Trishuli), and Dhading. The river joins the Trishuli River in Rasuwa.

Trubhuwan Trishula High School—the oldest and biggest in the area—was either swept away or substantially damaged, cutting the area off from the rest of the Himalayan country.

“We have unconfirmed reports of casualties. We are gathering authentic information,” a disaster management official said.
The police said a glacier that melted in Tibet caused the Bhote Koshi to flood around 9.15 am in Nepal.

भोटेकोसी नदी रसुवामा तिब्बत तर्फबाट ठुलो बाढी प्रवेश गरेकोले अर्को सूचना नआउँदासम्म त्रीशुली नदीको तटिय क्षेत्रका जिल्लाहरु नुवाकोट, धादिङ, चितवन, गोरखा लगायतका स्थानहरूमा उच्च सतर्कता सहित सुरक्षित स्थानमा रहन अनुरोध छ। pic.twitter.com/Zun6icZZCM

— Nepal Police (@NepalPoliceHQ) August 26, 2026

Officials said that information gathered from the Chinese side indicated that although the water levels in the Bhote Koshi were receding, the threat of fresh floods cannot be ruled out.

The affected route is part of Nepal’s over 260-year-old trade route with Tibet. At least half a dozen bridges over the Trishuli have also been swept away, including in the Malekhu area, obstructing travel towards two important tourist zones: Chitwan and Pokhara.

The aftermath of the devastating flash flood in Trishuli Bazaar, Nuwakot, Nepal. The footage shows widespread destruction, with floodwaters leaving debris and damaged structures across the area.

Video ©: Nuwakot Express. pic.twitter.com/hyuKt0wEXv

— Everest Today (@EverestToday) August 26, 2026

Initial reports also said that the floods affected at least 430 MW of power generation capacity.

Prime Minister Balendra Shah called an emergency meeting of the Cabinet. The Nepal Army has taken the lead in the rescue operations, and other security agencies are assisting it.

Nepal flash floods sweep away areas bordering Tibet: What we know so far

1. 105 Indian nationals missing: The travellers were in or travelling through the flood-hit Rasuwa region, with many understood to have been preparing to cross into Tibet for the Kailash Mansarovar Yatra. The Kathmandu Post reported that nearly 400 pilgrims, mostly Indian, were scheduled to cross the Nepal-China border on Wednesday, but travel routes and communications were disrupted by the flood. The Nepal Tourism Board has urged travellers and their families not to draw conclusions about anyone’s safety until the verification process is complete.

   The preliminary list was compiled from information provided by 10 tourism and travel agencies. The Tourism Board, Tourist Police and tourism stakeholders are verifying the whereabouts and safety of the travellers in coordination with travel agencies, guides, local authorities and security agencies. Among the 291 foreign nationals, India accounts for 105, while others include nationals of Australia, the Netherlands, the United States, Malaysia, the United Kingdom and South Africa. The nationalities of several other foreign travellers have yet to be confirmed, while 37 are listed as non-resident Indians (NRIs).

2. Flood hits area near China-Nepal border: The river originates in Tibet and flows into Nepal’s Trishuli River, which eventually enters India as the Gandak River. The cause of the flooding has not yet been established. The aftermath of the devastating flash flood in Trishuli Bazaar, Nuwakot, Nepal. The footage shows widespread destruction, with floodwaters leaving debris and damaged structures across the area.</
   

   Nepal flash flood –

   नेपाल में आई बाढ़ का एक और डरावना वीडियो। यह तस्वीर चीन अधिकृत तिब्बत के इमिग्रेशन सेंटर की है। बाढ़ की वेव करीब 5 मंजिला ऊंची इमारत को पार कर गईं। यहां पर शायद ही कोई जिंदा बच पाया होगा। बाढ़ की शुरुआत इसी एरिया से हुई, जो बाद में नेपाल में एंटर हुई। https://t.co/JiWboP9mSw pic.twitter.com/DYFAgNHZIr

   — Sachin Gupta (@Sachingupta) August 26, 2026

3. Timure and Syapru Besi among worst-hit areas: The flood severely affected Timure and Syapru Besi in Rasuwa district, with villages, market areas and infrastructure projects damaged or washed away. Authorities have warned residents along the Bhote Koshi and Trishuli rivers to move to safer ground as floodwaters move downstream.
4. At least 25 rescued as helicopters deployed: The Nepal Army said at least 25 people had been rescued by Wednesday afternoon, while helicopters were being used for search-and-rescue operations. Rescue efforts have been complicated by high water levels and difficult access to some of the worst-hit areas.
5. Houses, roads and bridges swept away: Floodwaters swept through settlements and market areas along the Bhote Koshi and Trishuli river systems, damaging homes, roads and bridges. The full extent of the destruction remains unclear as authorities continue to reach cut-off areas and assess the damage.
6. Over 12% of Nepal’s hydropower capacity affected: Nepal’s energy ministry said about 430 MW of electricity supply was affected, mostly from hydroelectric projects. That is more than 12% of Nepal’s total hydropower capacity of about 3.2 GW, according to a Reuters calculation. Several hydropower and transmission facilities were damaged.
7. Health authorities and WHO mobilise assistance: The government has mobilised medical teams and ambulances for the affected areas, while the World Health Organization is preparing medical supplies and equipment to support the emergency response. Kathmandu hospitals have also been placed on alert as authorities assess the health needs of affected communities.
8. Cause under investigation, GLOF possibility examined: Authorities have not confirmed what triggered the sudden surge. Nepal’s Flood Forecasting Division said heavy rainfall in Rasuwa itself did not appear to explain the flooding, while satellite imagery showed significant rainfall on the Tibetan side. Officials are examining whether a glacial lake outburst flood (GLOF), landslide-related blockage or another sudden release of water may have triggered the disaster.
9. Tibet’s Gyirong reports ‘major casualties’: A mudslide on the Nepalese side affected Gyirong Port, a major China-Nepal border crossing in Tibet’s Gyirong county, according to Chinese state news agency Xinhua. Roads, communications and power supplies in the area were disrupted, while casualties and missing people were reported.
10. Xi orders ‘all-out’ search efforts: Chinese President Xi Jinping called for all-out search-and-rescue efforts for missing people and urged authorities to strengthen monitoring and early-warning systems to prevent secondary disasters.

(With inputs from agencies)