An ice-rock avalanche originating from a high-mountain glacier in Nepal has been identified as the cause of a devastating mudslide that struck Gyirong Port in southwest China's Xizang Autonomous Region on Aug. 26, local authorities said Sunday.

A glacier on the south slope of Mount Langtang Lirung in Nepal fractured at an altitude of about 5,200 meters, triggering an ice-rock avalanche, according to a press conference held by the information office of the regional government.

Rescuers carry out search and rescue operations at the mudslide-hit Gyirong Port in Gyirong County, southwest China's Xizang Autonomous Region, Aug. 29, 2026.  (Photo: Lhasa fire and rescue mobile detachment)

The avalanche plunged rapidly to an altitude of around 4,000 meters, scouring the mountainside and developing into a massive debris flow, which surged about 22 kilometers before reaching Gyirong Port at an altitude of around 1,800 meters.

The disaster flattened an area of about 0.7 square kilometers, destroying 27 buildings and related facilities in the area.

The findings were made by a cryosphere emergency disaster response team from the Institute of Mountain Hazards and Environment under the Chinese Academy of Sciences, based on the analysis of remote-sensing monitoring data and field-transmitted data, as well as on-site surveys and investigations.

The deadly mudslide had claimed 16 lives and left 546 others missing at Gyirong Port as of 6 p.m. Saturday, the regional government said on Sunday morning.