One person has been confirmed dead and 17 others are listed as missing in the floods on the Bhotekoshi River, said Arjun Paudel, chief district officer of Rasuwa district, AFP reported.
The wall of water that hit Tuesday morning also swept away one of the main bridges linking Nepal and China.
Eleven Nepalis and six Chinese people are among the missing, Nepal’s National Disaster Risk Reduction and Management Authority said.
Deadly floods and landslides are common across South Asia during the monsoon season from June to September but experts say climate change is making them worse.
The UN’s World Meteorological Organization said last year that increasingly intense floods and droughts are a “distress signal” of what is to come as climate change makes the planet’s water cycle ever more unpredictable.
The Katmandu-based International Center for Integrated Mountain Development (ICIMOD) warned in June that communities face heightened disaster risks this monsoon season.
“Rising temperatures and more extreme rain raise the risk of water-induced disasters such as floods, landslides, and debris flows,” ICIMOD said.