According to National Disaster Risk Reduction and Management Authority (NDRRMA) Director General Dinesh Bhatta, the flood might be caused by the outburst of a glacial lake situated near the Nepal-China border, as there was no excessive rainfall at that time on both sides of the border.

Dozens of rescuers searched the banks of a mountain river Wednesday looking for people missing after monsoon floods swept away Nepal's main bridge connecting to the country to China and caused at least nine deaths.

At least eight people were killed and over two dozen were missing after the Bhote Koshi River flooded, washing away the "Friendship Bridge" that links China and Nepal, officials said on Tuesday.