Illegal expansion of a dam caused the landslide in a gold mine in northwestern Shaanxi Province, the local government announced Sunday.

The Zhen'an County Gold Mining Co. Ltd., owner of the mine, has been raising the height of the dam without official authorization since the company was established in 1993, increasing the capacity of the dam from 300,000 cubic meters to nearly 1 million cubic meters, said Ma Yanping, deputy director of the provincial administration on production safety.

"The blind expansion led to part of the dam collapsing when it was undergoing its sixth heightening project," said Ma, adding that they found both designers and builders on the expansion project had been working without official licenses.

Seventeen people are still missing from the accident that happened on April 30 in Zhen'an County and they are unlikely to survive. The accident occurred at 6.40 PM when the dam collapsed and a large amount of gold ore tailings buried about 40 rooms of nine households, leaving 17 residents missing and five others injured.

The missing people were possibly buried under ore tailings and the remainder of the dam is unstable which is hindering rescue work, said Ma.

More than 130 local residents have been evacuated from the site of the accident and resettled elsewhere.

The local government has taken emergency measures to prevent the poisonous content in the tailings, including sodium cyanide, from polluting the environment. Further investigation into the cause of the accident is underway.

The county-level Gold Mining Co. Ltd. has a daily processing capacity of 500 tons of gold ores.

(Xinhua News Agency May 8, 2006)