The death toll from catastrophic flash floods and mudslides along the Nepal-China border rose to about 1,375 on Saturday, 10 days after an ice-rock avalanche triggered a massive debris flow through valleys on both sides of the border, according to official figures.
Nepal reported 1,344 deaths, while Chinese authorities said at least 31 people were killed in the southwestern Xizang Autonomous Region, also known as Tibet.
About 5,531 people remained missing, including roughly 850 foreigners, according to combined figures from the two countries.
Nepal's National Disaster Risk Reduction and Management Authority said about 5,000 people were still missing in the country, including 589 foreigners.
Chinese authorities reported another 531 missing in Xizang.
The figures have shifted as rescue teams recover bodies and authorities reconcile reports from remote and heavily damaged areas.
The disaster began Aug. 26 when a large section of rock and ice on the northern flank of Mount Langtang Lirung fractured at an elevation of about 5,200 meters (17,060 feet).
The collapse unleashed a huge ice-rock avalanche that raced down the mountain before rapidly transforming into a debris flow carrying massive amounts of rock, mud, ice and water.
The torrent swept through the Lhende Khola valley along the Nepal-China border and reached the area around the Gyirong border crossing in Tibet, a key trade and transit route between the two countries.
The force of the avalanche and resulting debris flow temporarily blocked rivers, creating unstable natural dams and lakes that later overflowed or breached.
The resulting surge sent floodwaters and mud through downstream valleys and into Nepal's river systems.
In Nepal, the disaster devastated parts of Rasuwa, Nuwakot, Dhading and Kavre districts, as well as areas of the Kathmandu Valley and communities farther downstream.
Villages were buried or swept away, while roads, bridges, homes, schools and other critical infrastructure were destroyed or severely damaged.
Several hydropower projects along the Trishuli and Bhote Koshi river corridors were also hit.
Hundreds of workers were trapped in tunnels and facilities at some sites, prompting prolonged search-and-rescue operations. Some survivors were found and rescued more than a week after the disaster.
The scale of the flooding carried debris and bodies far downstream. Some remains were recovered as far as 240 kilometers away in neighboring India, further complicating identification efforts.
On the Chinese side of the border, the Gyirong crossing was largely buried beneath mud and debris, with buildings, vehicles and other infrastructure damaged or destroyed.
Access to the area remained difficult because of damaged roads, continuing landslide risks and unstable water bodies left behind by the disaster.
Tens of thousands of rescue workers from the Nepali Army, Nepal Police and Armed Police Force took part in the response, alongside Chinese teams and international assistance.
Helicopters and heavy machinery were deployed to reach isolated communities and clear roads blocked by mud, rock and debris.
More than 13,000 people had been rescued in Nepal, authorities said.
Rescue crews faced treacherous terrain, continuing rainfall, blocked transportation routes and the threat of additional flooding caused by unstable debris dams.
The condition of many recovered bodies also made identification difficult, leaving families waiting for confirmation of missing relatives.
Humanitarian agencies said the disaster affected more than 90,000 people, while widespread damage to transportation, power and other services disrupted the lives of many more.
Early assessments put property damage in Nepal at more than 387 billion Nepali rupees, or about $2.57 billion.
Scientists have warned that the disaster highlights the growing risks facing communities in the rapidly warming Himalayas.
Rising temperatures are contributing to glacier retreat and may increase instability in high-altitude slopes through changes in permafrost, precipitation and other environmental conditions.
Chinese officials and some analysts have linked the disaster to broader climate-related changes in the region, although scientists are still investigating the specific factors that caused the Langtang Lirung slope to fail.
The event illustrates how hazards in high-mountain regions can rapidly cascade. An ice and rock collapse can trigger a debris flow, block rivers and ultimately produce devastating floods far downstream. Similar chain-reaction disasters have occurred elsewhere in the Himalayas, including the deadly 2021 Chamoli disaster in northern India.
As of Saturday, authorities on both sides of the border continued searching for missing people, recovering and identifying remains and providing assistance to displaced survivors.
Rescue operations were increasingly being accompanied by efforts to restore roads and other critical infrastructure and address the longer-term humanitarian and economic damage.
The disaster ranks among the deadliest natural disasters in the recent history of the Nepal-Tibet border region.
