A huge wall of mud and rock collapsed into a river on the Himalayan border of Nepal and China’s Tibet on Wednesday, triggering catastrophic flooding on the Nepali side that killed at least 98 people and left hundreds of tourists missing.

In a still-unfolding disaster, verified videos showed dozens of people swept away at the border, with authorities on both sides fearing far higher casualties and massive destruction.

Houses, roads and power projects were swept away in Nepal, while officials in Tibet said they feared “major casualties”, with some people missing in the county of Gyirong after a mudslide hit a border land crossing.

Initial reports suggested an earthquake in the area could have triggered an avalanche and caused the floods, Nepal’s foreign minister, Shisir Khanal, told the country’s parliament on Wednesday, local media reported.

FIXED CAMERA FOOTAGE SHOWS PEOPLE FLEEING

Security footage captured on the Chinese side of the Nepal-Tibet border showed many people fleeing before a torrent of rock, mud and water destroyed buildings, vehicles and took many lives.

With the deluge of muddy water sweeping down from an estimated nearly 2,000 metres (6,560 feet) above sea level, flood alerts were issued in the populous northern Indian states of Uttar Pradesh and Bihar, which border Nepal and where several rivers flow down the mountains into the plains.

Authorities in Bihar said they had evacuated about 5,000 people from six districts and planned to evacuate a total of 10,000 to 12,000 people.

At least 341 foreign travellers were missing from the region, including more than 100 Indians, three U.S. citizens and 12 British nationals, Nepal’s tourism ministry said. Dozens of local people were also missing.

Rescue teams in Nepal had recovered 95 bodies so far, police said. Local media reported 65 people were being treated in hospitals in the area and in the capital Kathmandu.

South Korea separately said that eight of its nationals working on a hydropower plant were missing.

EXPERT FEARS A SECOND FLOOD

The exact cause of the mudslide could not be immediately determined, but the German Research Centre for Geosciences (GFZ) said there was a 4.4 magnitude quake approximately seven minutes before the time shown on the security footage time-stamp.

An initial study of Planet Labs satellite imagery indicated that a landslide of snow and rock triggered a debris-laden flood in the Lhende river, about 20 km (12 miles) northeast of the Nepal-China Rasuwagadhi border crossing, Nepal’s National Disaster Risk Reduction and Management Authority said on X.

Before and after images from Planet Labs appeared to show a wide swathe of destruction on either side of the usual river course.

Qianggong Zhang, head of climate and environmental risks at the Kathmandu-based International Centre for Integrated Mountain Development, said the cause of the ice-rock avalanche into the Lhende Khola river on the Nepali side was yet to be confirmed.

“With a blockage still lodged upstream on the Nepal-China border river, authorities warn a second flood may occur,” Zhang said.

Rescue helicopters could not land in Nepal’s affected areas of Syapru Besi and Timure in the mountainous district of Rasuwa, with a population of about 50,000, officials said, with the river flowing above its normal course.

Television images showed collapsed homes, floating cars and a metal bridge being washed away, while witnesses told Reuters the waters engulfed entire villages.

“There could be heavy casualties or loss of property,” said district administrator Narendra Pariyar, who urged dwellers on the banks of the Bhote Koshi river — into which the Lhende Khola empties — to move to higher ground.

“There is devastation everywhere we look,” Tula Bahadur BK, a health worker in Rasuwa, told Reuters. “The settlements next to the river have been completely swept away. Five of my own relatives are missing.”

CHINA SAYS GYIRONG PORT AFFECTED

China’s official Xinhua news agency said the mudslide hit the Gyirong port, cutting roads, communications and power links in the Shigatse region near the border, but did not elaborate.

Chinese state broadcaster CCTV said authorities had deployed 601 personnel and 113 vehicles, along with search dogs and rescue equipment, to conduct emergency operations.

A rescuer interviewed by CCTV said they had been trying to establish contact with the Gyirong border port but “so far there haven’t been any results”. All roads leading to the border crossing had been “completely destroyed” after a preliminary inspection with a drone, the rescuer added.

“The mudslide situation is indeed quite severe,” he said. “The mud is very thick, and the weather is a major concern — it’s been raining continuously, so water levels could rise at any time.”