State television said Xie had resigned due the administration's failure to address the crisis. The State Council, or cabinet, and Communist Party had approved it.

The administration "as the main body for environmental protection did not pay enough attention and fell short of the evaluation about the possibly severe results out of the incident. Thus, it holds the responsibility for the losses," China Central Television said.

The high-level reshuffle follows mounting criticism over the government's handling of the spill - most of it aimed at officials in Jilin province - where a blast at a chemical plant poured 100 tonnes of cancer-causing benzene into the Songhua River on Nov. 13, for failing to report it.

The move is also in line with a campaign by President Hu Jintao to instil official accountability in the highest levels of government, dating back to the sacking of the health minister and Beijing mayor after a cover-up of the deadly outbreak of Severe Acute Respiratory Syndrome in 2003.

The environmental protection administration said from Nov. 14 to Nov. 17 it received no reports from Jilin provincial authorities, meaning the "best opportunity" to control the spill had been lost, the China Daily newspaper quoted Administration Vice-Minister Wang Yuqing as telling a national teleconference.

"A reckless pursuit of economic growth and a lack of emergency response mechanisms have seen China experiencing a high rate of environmental disasters," Wang was quoted as saying.

The toxic slick forced officials in Harbin, a city of 9 million people downstream from Jilin in Heilongjiang province, to shut off its water for five days. The slick passed the city on Sunday and is making its way through Heilongjiang toward the Russian border.

Caijing Magazine noted in a commentary that Beijing officially notified Moscow of the problem only on Nov. 22.

The environment director, Xie, had "contended that the toxic chemicals were gradually diluted as they were carried down the river, so 'it was not to late' to inform the Russians then," Caijing said.

"In the realm of foreign relations, however, such an explanation does not go over too well," it said.

The slick was winding its way northeast towards the Siberian city of Khabarovsk, through areas populated by millions of Chinese, and on Friday it was passing through the town of Dalianhe, where water supplies were cut off on Thursday.

The community of 67,000 was relying on well water and tapping into supplies from neighbouring communities, a town official said by telephone. Schools were closed and classes would not likely resume until next Tuesday, when the pollutants were due to have passed by the town, a teacher said.

Downstream in Jiamusi city, officials shut down a major water plant near the river serving 2.4 million people to prevent contamination. They were tapping groundwater and deepening wells before the belt of pollution reaches, likely by next Tuesday, Xinhua news agency reported.

Cold weather also was freezing the Songhua, slowing the movement of the slick, it said.

By the end of November, 36 major pollution accidents had been reported, the environment administration's Wang said, warning that there could be more that have gone unreported.

Regional governments were giving tacit consent to discharges of pollutants into rivers and some had approved polluting businesses that the central government had banned, Wang said.

"Local environmental protection bureaus need to increase their ability and improve their equipment to supervise and handle pollution," he said.