Rescuers have yet to find any survivors after a landslide early on Friday buried 83 Chinese miners as they slept near the Tibetan capital, Lhasa.
Chinese state-run media say more than 1000 emergency workers have been sent to the disaster site at an altitude of 4600 metres.
State television reported that the landslide had engulfed a large area, including huts where the miners slept.
The mine is operated by a subsidiary of state-owned China National Gold Group, China's biggest gold producer.
Reports said most of the workers were ethnic Han Chinese, with two thought to be ethnic Tibetans. Most were said to be migrant workers from Yunnan, Guizhou and Sichuan provinces.
A vast amount of debris and land engulfed the workers' camp in Maizhokunggar county, Xinhua news agency reported.
Police said the area that collapsed was up to four square kilometres. Local hospitals had been put on alert to expect casualties.
Chinese officials believe the Tibetan plateau has huge resources, including millions of tonnes of copper, lead, zinc and iron ore.
