A massive flash flood in Nepal's northern Rasuwa district, close to the Tibet border, has triggered a major humanitarian emergency, leaving 105 Indian nationals missing and at least nine people dead.

The sudden surge of water swept through settlements, damaged key infrastructure and washed away vehicles, bridges and project sites in the border region. As floodwaters continued to travel downstream, authorities in Bihar also stepped up monitoring and preparedness measures.

Officials said the floodwaters entered the Bhote Koshi river from the Tibetan side at around 9 am, causing extensive damage in and around Timure and Syapru Besi.

The exact trigger behind the disaster is still being investigated.

Possible GLOF among causes being examined

Nepal's Flood Forecasting Division said local rainfall in Rasuwa did not appear sufficient to explain the scale of the flooding. Satellite observations, however, indicated significant rainfall on the Tibetan side of the border.

Authorities are also examining whether a glacial lake outburst flood, or GLOF, could have contributed to the sudden surge.

A separate mudslide was reported near the Gyirong border crossing in Tibet, where casualties and missing persons were also reported.

Dramatic videos from the affected areas showed powerful currents tearing through the landscape. In one clip, a bridge was seen being carried away by the force of the water, while another showed a house collapsing as residents fled in panic.

Border market, police posts and bridge damaged

The destruction has severely affected areas close to the Nepal-China border.

Timure Bazaar and the adjoining customs zone reportedly suffered extensive losses, with floodwaters carrying away vehicles and commercial goods. A Friendship Bridge at Rasuwagadhi, rebuilt after a deadly flood in the region last year, was also destroyed.

Three Nepal Police facilities were damaged in the disaster, including installations in Timure, Syaphrubesi and Rasuwagadhi. Nine personnel of Nepal's Armed Police Force deployed near the border were reported missing.

Hydropower facilities, roads and bridges were also hit. Nepal's Energy Ministry said the flooding affected around 430 MW of electricity generation, largely from hydropower projects.

The Rasuwa Bhote Koshi flood has since moved towards Narayani Devghat, with authorities warning that water levels could continue to rise. Residents and businesses located along the river have been advised to remain vigilant and shift to safer areas if required.

Rescue efforts face major challenges

Nepal has launched a large-scale search and rescue operation involving the police, Nepal Army and Armed Police Force.

Prime Minister Balendra Shah chaired an emergency Cabinet meeting to assess the damage and coordinate the response. Army helicopters were deployed towards the affected region, but high water levels prevented them from landing in some of the worst-hit locations, including Syapru Besi and Timure.

Authorities have also issued warnings for communities located downstream in the Trishuli river basin, including parts of Nuwakot, Dhading, Gorkha and Chitwan.

Road traffic from Kathmandu towards several affected districts was suspended as a precaution.

Nepal's Home Minister Sudan Gurung appealed to people living along the Bhote Koshi and Trishuli rivers to move away from vulnerable areas and follow evacuation instructions.

Flood threat reaches Bihar's radar

The situation has also prompted concern in Bihar, as the Bhote Koshi flows through Nepal before joining the Trishuli river system. The river network eventually connects with the Gandak, which enters India.

Bihar Chief Secretary Pratyaya Amrit held a video conference with district magistrates and directed districts linked to the Gandak and Kosi river systems to maintain heightened vigilance.

Chief Minister Samrat Choudhary said senior officials were monitoring developments and that a high-level team had been formed to keep track of the situation.

Flooding and casualties reported in Tibet

Across the border in China, a mudslide hit Gyirong county and the Gyirong port area, disrupting roads, electricity and communication networks in parts of the Shigatse region.

Chinese authorities reported casualties and missing people, while President Xi Jinping called for an intensive search operation and stronger systems to monitor potential secondary disasters.

The Chinese Embassy in Nepal also activated its emergency response mechanism to assess the impact on Chinese citizens and businesses in the affected region.

The Rasuwa region had witnessed a similar tragedy last year when flooding in the Bhote Koshi killed nine people and left 24 others missing. That disaster also destroyed a bridge connecting Nepal and China and disrupted cross-border movement and trade for months.

As rescue teams struggle to access some of the worst-affected areas and floodwaters continue their journey downstream, authorities in Nepal, Tibet and Bihar remain on alert, with the search for the missing still underway.