A high-altitude ice avalanche in Nepal triggered a chain of events that evolved into a devastating mudslide and struck Gyirong Port in southwest China's Xizang Autonomous Region, according to China's Ministry of Natural Resources.

A powerful mudslide struck Gyirong County in Xizang on Wednesday. The Ministry of Natural Resources activated a Level-II geological disaster emergency response at 3 p.m. the same day and dispatched a working group to the site to assist with emergency rescue efforts and the prevention of further geological disasters.

The high-altitude ice avalanche upstream in Nepal led to a debris flow that later developed into a mudslide, according to the ministry.

Guo Zhaocheng, a senior engineer at the China Aero Geophysical Survey and Remote Sensing Center for Natural Resources, said high-resolution remote sensing images and expert analysis show that the high-altitude ice avalanche occurred on the upper reaches of Cuojian, a tributary of the Donglin Zangbo River in Nepal.

The collapsing ice scraped up moraine deposits along the valley, forming a high-speed debris flow that continued downstream before evolving into a mudslide, which surged toward Gyirong Port, causing major casualties.