Authorities were scrambling on Thursday to recover 3,000 barrels full of hazardous chemicals that were washed into a major river in northeastern China by recent flooding.
A total of 7,000 barrels were swept into the Songhua river in Jilin province on Wednesday following heavy rains, but most were empty, according to reports.
However 2,500 barrels containing 510 tonnes of combustible, colourless chemicals and 500 loaded with solvents were washed into the river from two chemical plants near the city of Jilin, state-run Xinhua news agency said.
At least 400 barrels had been recovered on Thursday, city officials told Xinhua.
The city's water supplies were restored on Thursday after being cut off the day before due to the incident, leaving 4.3 million people dependent on bottled water.
Jilin is the latest province to be hit by deadly floods that have killed 333 people since July 14 and left another 300 missing, according to the latest official figures.
Local environmental protection authorities monitoring the water quality of the Songhua river have so far detected no contamination, official media reports said.
In 2005, millions of people in northeastern Heilongjiang province were left without water for four days after an explosion at a benzene factory spilled the carcinogenic chemical into the Songhua River.