Catastrophic flash flooding has struck the border region between Nepal and China, leaving at least 17 people dead and hundreds missing. Harrowing footage captured the moment a massive surge of water and mud descended from the mountains, overwhelming a border crossing building and forcing terrified people to flee.

The disaster is believed to have been caused by a wall of mud and rock collapsing into a river, leading to severe flooding on the Nepali side. Initial reports suggest the floods may have been triggered by an avalanche resulting from an earthquake, according to Nepal’s foreign minister.

The German Research Centre for Geosciences registered a 4.4 magnitude earthquake approximately seven minutes before security footage recorded the event at the border.

The torrent of water and debris has destroyed homes, roads, and businesses in Nepal. Tibetan officials have expressed fears of significant casualties in the aftermath.

Flood alerts have been issued for downstream areas in the northern Indian states of Uttar Pradesh and Bihar.

According to Nepal’s tourism authority, at least 384 foreign travelers are missing. Among them are three U.S. citizens, 105 Indian nationals, 93 Nepalis, and 12 British nationals.

Rescuers transport an elderly woman in a tractor after a flash flood in Nepal.

Rescuers are working in the affected areas, transporting survivors and assessing the damage. The full extent of the disaster is still unfolding.