Rescuers search for survivors at the site of ice avalanche in southwest China's Tibet Autonomous Region. The avalanche has been confirmed as a glacier slide. [Photo: Xinhua]

The avalanche in southwest China's Tibet Autonomous Region on Sunday was a glacier slide, it has been confirmed.

A 600-meter rescue passage had been completed Wednesday morning, but no signs of life have been detected.

Nine people, buried by the icefall in Dungru Village in Rutog County, Ngari Prefecture, on Sunday, were confirmed dead on Monday.

Rescuers have moved more than 45,000 cubic meters of ice and snow.

"Rescue work is continuing, while the cause of the ice avalanche is being investigated to avoid secondary disasters", said Zhang Jianping, a police officer directing the rescue.

UAV aerial images show that the icefall took place between glaciers on two snow-capped mountains at an altitude above 6,000 meters. The volume of the icefall was estimated at 600 million cubic meters, enough to fill a large reservoir.

Experts believed that the icefall is a result of global warming, which has caused melting and cracking of the glaciers.

They warned that more icefall and avalanches are likely to occur in the plateau region. A dozen households have been evacuated while rescue work continues.