WATCH: Wall of water engulfs people, vehicles in seconds at Nepal-China border in terrifying video

Terrifying CCTV footage from the Nepal-China border has captured the extraordinary speed and force of Wednesday's deadly flash floods, showing people desperately running for safety moments before a wall of muddy water and debris engulfs the area.

The footage, recorded at Gyirong Port in Tibet directly across from Nepal's Rasuwa district, begins with vehicles parked around the border facility and people moving through the area. Within moments, the scene changes dramatically. A massive brown torrent carrying mud, rocks and debris rushes down from upstream. People can be seen running as the flood rapidly spreads across the facility, swallowing the open space and sweeping vehicles away.

A thick cloud of dust, spray and debris then obscures much of the scene. The footage provides one of the starkest visual records yet of the disaster that struck the mountainous Nepal-Tibet border region on Wednesday morning.

People run as torrent approaches

Another sequence from the border area shows dozens of people scrambling away as the approaching torrent bears down on buildings and vehicles. The water reaches the area with such speed that those caught in its path appear to have only seconds to react. Cars and buses are overwhelmed by the current, while parts of the infrastructure disappear beneath mud and debris. Separate footage from Gyirong shows a multi-level parking structure packed with cars and buses being overwhelmed. As floodwaters surge around it, the structure gives way and vehicles tumble into the raging current.

The devastation then spreads across what had moments earlier been a functioning border complex. Videos emerging from the Nepal side show similarly dramatic destruction. One clip captures floodwater surging towards a bridge as buildings nearby are swept away. Within about half a minute, the bridge itself collapses into the muddy torrent.

Another recording shows houses giving way under the force of the water, while footage from a residential area captures buses standing partly submerged. In one particularly distressing video, a woman can be heard crying out for her missing daughter as floodwaters surround the area.

Flood crossed into Nepal

The torrent struck Gyirong before sweeping across the international border into Nepal's Rasuwa district and causing widespread destruction along the Bhote Koshi river system. Officials said the Bhote Koshi began flooding at around 9 am local time. The disaster subsequently affected Rasuwa as well as downstream areas including Nuwakot and Dhading. Timure and Syapru Besi were among the places badly hit, while the customs and trading infrastructure around the Rasuwagadhi border crossing suffered extensive damage.

The flood destroyed or damaged houses, roads, bridges and hydropower facilities as it travelled through the narrow Himalayan valleys. The Nepal Electricity Authority said around 430 MW of power-generation capacity, including hydropower and solar installations, was affected by the disaster.