ZIJIN Mining Group Co, China's leading gold producer, has been asked to restrict the mining of gold after its copper mine polluted a river in southeast China's Fujian Province, according to a statement on the Shanghai Stock Exchange yesterday.

The local government of Shanghang County, where Zijin is headquartered, made the decision to limit the company's output to a level that can ensure the safety of environment, the statement said.

Trading of the company's stock was suspended for two days in Hong Kong and Shanghai pending the announcement.

The decision is expected to cut the company's gold output by 1 ton a year. Statistics show Zijin produced 75.37 tons of gold in 2009, up 31.05 percent from the previous year.

On July 3 and 4 about 9,100 cubic meters of waste water spilled from a sewage tank at a copper plant owned by Zijin into the Tingjiang River in Fujian Province, killing thousands of fish.