Environment officials and senior executives of a state-owned petroleum company and its listed subsidiary have been punished for a toxic river spill a year ago that forced officials to temporarily cut off water to millions living in northeastern China and Russia, state media reported Friday.

The accident, one of China's worst toxic spills, occurred in November 2005 when an explosion at a chemical plant discharged tons of benzene and other dangerous chemicals into the Songhua River in Jilin province.

Xinhua News Agency said the State Council, China's Cabinet, meted out "administrative punishments" to senior executives of the state-owned China National Petroleum Corp. and its New York- and Hong Kong-listed subsidiary, PetroChina Co. Ltd.

Administrative punishment usually means the person is given a warning, demoted or removed from his or her position.

Duan Wende, vice general manager of the China National Petroleum Corp. and senior vice president of PetroChina, which owned the plant, received a demerit on his personal record, Xinhua said.

Nine other executives, including Yu Li, board chairman and general manager of the Jilin branch of PetroChina, were either given serious warnings, demoted or dismissed, the report said, but did not give details.

Wang Liying, director of the Jilin provincial environmental protection department, was given a "serious demerit" on his record, according to the report.

A State Council investigation showed the Nov. 13, 2005, explosion was caused by negligence and a failure to observe regulations on the plant's operations, Xinhua said.

The blast killed eight people and injured 60, but also forced authorities to shut off water supplies to 3.8 million people in the city of Harbin for five days, and strained relations with Russia, because the Songhua River feeds other rivers that flow through the Russian Far East city of Khabarovsk.

Local authorities were accused at the time of reacting too slowly to the accident and delaying public disclosure of the spill.

Most of China's canals, rivers and lakes are severely tainted by agricultural and household pollution. Chinese leaders say the country faces a critical water shortage, partly due to chronic pollution and chemical accidents.

In August, China said it would spend $125 billion to improve water treatment and recycling by 2010 to fight the mounting threat of urban water pollution.