Rescue work is under way for 83 landslide-trapped workers in Tibet.

The landslide happened in Maizhokunggar County of Lhasa, the regional capital, at about 6am local time yesterday.

The victims were workers from Tibet Huatailong Mining Development Co Ltd, a subsidiary of the China National Gold Group Corporation.

The affected area has been classed as a natural disaster.

The area is 3km long and contains about two million cubic meters of mud, rock and debris, according to the publicity department of the regional government.

More than 2,000 rescuers, including police, firefighters and medical personnel, are working at the site, which is at an altitude of 4,600 metres.

About 200 large vehicles, 15 sniffer dogs and 15 life-detector machines are being used in the rescue.

The rescue is said to be very difficult due to low temperatures.

A mass of rolling rocks from the mountain top sliced a massive excavator in two, a witness said.

The broken boulders buried the workers' camp, which is 2km away from the mountain pass.

Chinese President Xi Jinping has ordered that the exact cause of the disaster be determined and no effort be spared to find any survivors.