Vice Minister of the State Environmental Protection Agency (SEPA) Wang Yuqing angrily blamed Jilin officials for covering up a November 13 benzene spill into the Songhua river that resulted in an 80 kilometer (50 mile) long toxic slick now floating downstream toward Russia.

"When a big pollution incident happens, the local environmental protection departments must promptly report the pollution situation to the agency," Wang said on the agency's website.

"We will not allow the cover-up of the truth. You cannot delay the report and delay prompt counter-measures."

The spill, which came after a massive explosion at a PetroChina chemical plant in Jilin city, resulted in a five-day cut of water supplies to 3.8 million residents in Harbin, capital of Heilongjiang province, last week.

Jilin officials covered up the disaster for nearly 10 days before informing the public. Wang said SEPA was investigating who ordered the cover-up.

He said the incident was partly the result of the unchecked economic development that has seriously damaged China's environment during some 25 years of fast-paced growth.

"At present, the blind pursuit of development in some localities is placing huge pressures on protecting the environment. The situation is extremely serious," Wang said.

"In some places, no one is paying attention to environmental protection work, no clear preparations are in place to address sudden and major environmental accidents, our work on emergency information and response is inadequate and our envrionmental emergency monitoring capacity is no good."

China was closely monitoring the slick as it moved toward the Russian border and was cooperating with Russian authorities on a joint response to the spill. Beijing had also given the go ahead to UN environmental experts to monitor the situation.

"We will keep close cooperation with the Russian side so as to minimize the possible impact of the pollution on the Russian side," foreign ministry spokesman Qin Gang told journalists Thursday.

Qin's remarks came as authorities said the chemical slick was moving more slowly down-river than expected, which could result in a long-term hazard as more of the benzene is deposited in the river bed or on the banks.

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