"Xie submitted a resignation request to the Communist Party of China (CPC) Central Committee and the State Council. The request has been approved," said a joint circular from the general offices of the CPC Central Committee and the State Council, the Chinese cabinet.

Xie has become the highest-ranking official to be removed from office for an environmental incident, as the Chinese authorities are increasingly aware of the danger of seeking economic development at the cost of environment, as well as the importance of boosting government accountability.

The State Council said in a separate announcement that it has appointed Zhou Shengxian, former director of the State Forestry Administration, as Xie's replacement.

"After this major water pollution incident (in the Songhua River) occurred, the SEPA has failed to pay sufficient attention to the incident and has underestimated its possible serious impact," said the joint circular.

"It should bear due responsibility for the losses caused by this incident," the circular added.

Around 100 tons of pollutants containing hazardous benzene spilled into the Songhua River after a chemical plant explosion on Nov. 13 in northeast China's Jilin Province. The incident has forced cities along the river, including Harbin, capital of Heilongjiang Province and a city of more than three million people, to temporarily suspend water supply.

As the pollutants are also expected to flow into a major border river between China and Russia, diplomatic efforts and environmental cooperation are now underway to minimize the impact of trans-border pollution.

The central authorities' joint circular on Friday ordered relevant departments to step up investigation into causes of the explosion and pollution incidents, and vowed to "seriously punish those responsible."

Jiang Chengsong, a member of the Environmental and Resources Protection Committee of the National People's Congress, China's top legislature, said the quick replacement of the environmental chief after the Songhua River pollution incident also shows the improvement of China's political system.

"It indicates that the country's official accountability system has become more mature," he said.

China activated the official accountability system during the SARS (severe acute respiratory syndrome) crisis in 2003. More than1,000 officials, including then Health Minister Zhang Wenkang and Beijing Mayor Meng Xuenong, were ousted for their attempts to cover up the epidemic situation or incompetence in SARS prevention and control.

The system was later introduced to all levels of the government, and more officials lost their jobs for major accidents or other administrative mistakes. In April 2004, General Manager of the China National Petroleum Corporation Ma Fucai, also a minister-level official, resigned over a major oil well blowout accident in southwest China's Chongqing Municipality.

Born in 1949, Xie is a native of Tianjin. He became chief of the SEPA in 1993 after nearly two decades of service in it.

(Xinhua News Agency December 3, 2005)