The flash flood struck the Gyirong Township in the Tibet Autonomous Region on Wednesday morning. It swept through villages and towns near the China-Nepal border area, killing three in Tibet and 359 in Nepal, and leaving hundreds of others missing. State-run Xinhua news agency quoted local officials as saying that 558 people were reported missing in Tibet after a massive flash flood that caused heavy casualties.

The rescue work is hampered by a huge barrier lake, which Chinese officials, carrying out relief operations at the site, apprehend will cause a massive secondary disaster.

A team from China Anneng arrived in Gyirong County on Thursday with communications and detection equipment to collect key data and support efforts to address an upstream blockage or barrier lake, which is a top priority, Xinhua reported.