HARBIN, China (AP) -- China's government defended its handling of a chemical plant explosion that sent a 80-kilometer-long (50-mile) toxic slick of river water coursing through a major city and blamed the disaster on a subsidiary of a state-owned oil company.The benzene slick on the Songhua River in northeast China flowed into Harbin days after the city of 3.8 million people shut down its water system, setting off panicked buying that cleared supermarket shelves of bottled water, milk and soft drinks. The government said it would take about 40 hours for the chemical to pass the city.A government official said Thursday that local leaders were warned of the chemical threat after the November 13 blast that killed five people, and no one was sickened."It was handled properly," Zhang Lijun, deputy director of the State Environmental Protection Administration, told a crowded news conference in Beijing. "Authorities acted that day, and not one person has been sickened."The government did not publicly confirm that the Songhua had been poisoned with benzene until Wednesday, 10 days after the explosion. But Zhang said local officials and companies stopped using river water immediately after being told.The disaster has highlighted the environmental damage caused by China's sizzling economic growth and the complaints that the secretive communist government is failing to enforce public safety standards. The government says all major rivers are dangerously polluted and many cities lack adequate drinking water.With its huge population, China ranks among countries with the smallest water supplies per person. Hundreds of cities regularly suffer shortages, and protests over water pollution have erupted in rural areas.Downstream from Harbin, authorities in the Russian border city of Khabarovsk complained they had not received enough information on the threat. The Songhua flows into the Heilong River, which flows into Russia, where it is called the Amur River.But Zhang said Beijing has shared information and might set up a hot line with Moscow. He suggested complaints were premature, saying the chemical would take two weeks to reach Russia. (Full story)The chemical plant, located in Jilin, a city about 200 kilometers (120 miles) southeast of Harbin, is operated by a subsidiary of China's biggest oil company, state-owned China National Petroleum Corp. Benzene is used in the manufacture of plastics, detergents and pesticides."We will be very clear about who's responsible. It is the chemical plant of the CNPC," Zhang said.Asked whether the company might face criminal charges or fines, he said that had not been decided.Environmentalists criticized the government for not taking action and informing the public sooner."The local government should have predicted the possible pollution, but they didn't," said Xue Ye, general secretary of the Chinese group Friends of Nature.Authorities noticed the chemical spill after a trail of dead fish was found in the Songhua, the official China Daily newspaper reported. It said a monitoring station found November 20 that benzene and nitrobenzene levels were far above state standards, with nitrobenzene at one point 103.6 times higher than normal.Zhang Lanying, director of the Environment and Resources Institute at Jilin University, told the official Xinhua News Agency that massive amounts of the toxin can cause leukemia.In Harbin, the city government tried to reassure the public by announcing it was trucking in millions of bottles of drinking water and digging 100 new wells. The city already has 917 wells serving hospitals and some residential areas.On Thursday, one shop owner, who would give only her surname, Jiang, said her sales had doubled to 25,000 bottles a day at 12 cents a piece. Authorities froze prices to prevent overcharging.Jiang, standing outside her shop in a brisk wind and subfreezing temperatures, said distributors were bringing in extra supplies."Whatever we need, we can get," she said.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.