Search efforts keep being suspended amid fears of further flash flooding.
Chinese state media said a barrier lake formed by a landslide on Saturday is now being assessed for risk, days after a separate one had already sparked concerns on both sides of the border.
The army and police have blocked access roads to the affected areas as authorities try to keep the number of people there to a minimum in case of another flood.
China has identified the home countries of most of the 261 foreign nationals missing after flash flooding in Tibet: Nepal, India, Latvia, the UK and the US.
Beijing said the death toll in Tibet has risen to 16, with 546 people still missing.
Chinese state media described it as one of the most serious cross-border disasters in recent years, and linked it to glacier instability caused by global warming.
The Red Cross says the catastrophe has affected more than 90,000 people in Nepal.
The floods destroyed roads, bridges, hospitals and power stations, with the Nepalese government estimating reconstruction will cost around USD 5 billion.
(ał)
Source: IAR, Reuters, BBC