HARBIN, China - Harbin, one of China's biggest cities, on Wednesday temporarily restored water supplies shut off at midnight to allow residents to stock up as a wave of polluted river water flowed towards the area.
China confirmed earlier on Wednesday that an explosion at a petrochemical plant had caused "major pollution" of the Songhua River, from which Harbin, capital of northeastern Heilongjiang province, draws its drinking water.
The provincial government said an 80km stretch of heavily polluted water would reach the city at 5am on Thursday and flow past on Saturday, Xinhua news agency reported.
"As the exact time of the pollutants flowing to the city's drinking water intake spot has been confirmed, we hoped that citizens could take time to hoard as much water as possible ahead of the water cut-off," an executive from the Harbin water company was quoted as saying.
The executive said his company would halt supplies again when so ordered by the government of this metropolitan area of nine million people.
The polluted water contained nearly 30 times more than normal levels of chemicals containing benzene, an industrial solvent and component of petrol, the State Environmental Protection Administration said.
The provincial government had warned city residents to stay away from the river to avoid possible exposure to airborne contaminants coming off the water, Xinhua said.
Before the taps were closed at midnight on Tuesday, panicked residents rushed stores to stock up on food and water in a city where winter temperatures regularly drop below minus 20degC.
"All containers are being used to store water, including the bathtub," a factory manager told Reuters.
People were jamming the airport and rail stations to leave the area, a witness said.
Russia's environmental protection agency said on Wednesday it was worried that the pollution could affect drinking water supplies in its Khabarovsk region, which the Songhua enters several hundred kilometres downstream from Harbin.
The agency said the chemicals could reach water collection points for the city of Khabarovsk, just over the border from China, by Saturday, adding that it had asked the Russian Foreign Office to contact China about what pollutants were involved.
A Beijing Foreign Ministry spokesman said on Tuesday that China always took care of other countries' border water interests.
"Several major tributaries join the Songhua River on the downstream of Harbin," said a regional water official, who declined to give his name.
"It will help to lessen the degree of pollution."
The explosion that released the pollution happened in neighbouring Jilin province only a few hundred metres from the Songhua. Five people were killed in the blast.
Fifteen hospitals were on standby to take in contamination victims, Xinhua news agency said.
Prices of bottled water soared in recent days and state media said shops had been ordered to restore prices to normal to prevent panic buying.
"There is sufficient water. Residents have all stored a lot and we have been rushing in water from other places. We also have safe underground water," a government spokesman told Reuters.