According to state media, the mudslide from the Nepali side hit the Gyirong port, cutting off roads, communications and power in the Shigatse region near the border with Nepal.
Xi ordered all-out efforts to search and rescue people who are missing, Xinhua News Agency reported.
Meanwhile, across the border in Nepal, authorities said flash floods washed away villages while damaging roads, bridges and power projects.
The areas of Syapru Besi and Timure in the mountainous district of Rasuwa, with a population of about 50,000, were severely affected, officials said, while urging those living on the banks of the Bhote Koshi River to seek higher ground.
“We have reports of villages and infrastructure project sites being washed away,” district administrator Narendra Pariyar told Reuters, although no immediate estimates of casualties or property losses were available.
“There could be heavy casualties or loss of property,” he added.
“But I cannot say for sure now.”
The reason for the inundation was not immediately clear but a deadly flash flood on the same river last year was eventually traced to the draining of a glacier lake.
Nepal’s water resources ministry said hydroelectric projects were among the infrastructure damaged by the floods, along with roads and bridges.
Electricity supply in the area has been disrupted as a result of such damage, the government added.
Nepalese Prime Minister Balendra Shah said rescue and relief teams, as well as police and the military had been dispatched to help in the aid effort.
Last year’s flood in the Bhote Koshi killed nine people, with 24 missing, and washed away a “Friendship Bridge” linking Nepal and China to disrupt trade and transport for months. (Xinhua and agencies)
