Residents in northeast China's Heilongjiang Province are rushing to buy bottled water after thousands of barrels of chemicals were swept into the upper reaches of the Songhuajiang River in Jilin Province.

The incident has revived memories of the contamination of the Songhuajiang River in 2005 after an explosion at a petrochemical plant in Jilin Province left 3.8 million people in Harbin, the provincial capital of Heilongjiang, without drinking water for four days.

People were gathering in grocery stores and supermarkets to buy bottled water although the governments of Harbin and Jiamusi cities along the Songhuajiang River said domestic water supplies no longer came from the river.

Prices of bottled water have surged in some wholesale markets and grocery stores after the government said the water flow would enter Harbin in five or six days.

The wholesale price of "Kangshifu" mineral water has risen from 20 yuan (US$2.95) per box of eight bottles (1.5L/bottle) to 25 yuan, and "Nanbowan" brand from 7 yuan a box of 12 bottles(550ml/bottle) to more than 10 yuan, said a grocery store manager surnamed Yang, who was purchasing at the Liushunjie Mineral Water Wholesale Market of Harbin.

"As all producer stocks have been sent to Jilin Province, we have to raise the price as the demand has sharply increased," said a salesperson at the market.

Grocery store managers said some wholesalers were withholding stock in the hope that prices would soar further.

"I bought six boxes of water from the supermarket just in case," said taxi driver Liu Tao, 34.

"I thought my friends were joking when they told me to buy mineral water in 2005, but later as the water ran out, I couldn't get it at any price," Liu said.

"What if the time of water supply is limited? What if people are storing water and water pressure is influenced?" Liu said.

"It's summer after all. We need water," he added.

At the end of last year, the city closed the water intake from the Songhuajiang River and started to take water from Mopan Mountain, said Ji Quwen, deputy general manager of Harbin City Water Supply and Drainage Group.

The daily take was up to 900,000 cubic meters, enough to meet the daily demand of the city's residents, said Ji.

However, sales of bottled water had surged by 15 percent to 20 percent from late Wednesday to Thursday morning, said Huang Wenfu, deputy chief of market operations of the Heilongjiang Provincial Commerce Department.

Huang said stocks at large supermarkets such as Wal-Mart and Carrefour could meet demand for three days, allowing more water to be delivered.

The commerce department also contacted nearby Liaoning Province and Inner Mongolia Autonomous Region to discuss alternative supplies.

Officials with the provincial pricing department said emergency measures had been initiated to tackle profiteering and hoarding for speculation so as to keep prices of water and medicine stable.