Get the latest news and updates from Dawn

Devastating floods on the Nepal-Tibet border have killed at least 270 people, Nepali police said in an update on Thursday, a day after the disaster.

Chinese state media had earlier reported “major casualties” from a mudslide at a Tibet border hub with three dead, taking the total killed to at least 273.

A terrifying clip of surveillance video from the Chinese side of the frontier shows a massive wall of mud and debris crashing over a building several stories high on Wednesday morning, engulfing it as dozens of people ran for their lives below. The surge swept away buses and cars like they were toys.

Many of the missing are foreign tourists, officials said of the disaster, which the US Geological Survey believes was caused by a glacial collapse that sent a flow of debris engulfing areas along the way.