BEIJING - Workers on Friday struggled to recover 3,000 barrels filled with hazardous chemicals that were swept into a river in northeast China by floods, amid fears some had sunk, state media said.

Soldiers and emergency personnel fanned out at several points along the Songhua river in Jilin and Heilongjiang provinces to recover the barrels, which came from two factories damaged by floodwaters, Xinhua news agency reported.

A total of 7,000 barrels were known to be missing from the plants near the city of Jilin- 3,000 of them filled with trimethyl chloro silicane or hexamethyl disilazane, both colorless, toxic liquids.

So far, workers using cranes and steel nets have recovered about 3,000 barrels, but it was not immediately clear how many of them contained the chemicals, Xinhua said.

While tests have so far shown no signs of water contamination, workers tracking the barrels have apparently lost sight of some of them- fuelling fears they have sunk to the riverbed, making their retrieval more difficult.

The Songhua is the major source of drinking water for about 4.3 million people in the area. Prices of bottled water soared on Wednesday as worried residents cleared shop shelves, but then returned to normal, the China Daily said.

Water supplies in Jilin city were restored on Thursday after being cut off the day before.

Jilin is the latest province to be hit by deadly floods that have killed more than 300 people since July 14 and left another 300 missing, according to the latest official figures.

In 2005, millions of people in Heilongjiang province were left without water for four days after an explosion at a benzene factory spilled the carcinogenic chemical into the Songhua.