Emergency teams in north-east China are looking for thousands of chemical drums that washed into a major river after severe flooding.
Most of the barrels are said to be empty, but the others contain a flammable chemical used to make rubber and adhesive.
Hundreds have been recovered. The authorities say no chemicals have yet been found in the water.
The drums were washed into the River Songhua in Jilin City when floodwater swept through two chemical plants.
The spill happened as several parts of China were hit by flooding after heavy seasonal rain. The authorities say 928 people have been killed, and 477 more are missing.
In Jilin water supplies were cut for a while after the accident but were later restored.
“We test the water quality every half an hour,” said an environmental monitor.
The city suffered a major spill five years ago when an explosion at a petrochemical plant released tonnes of hazardous chemicals into the river. News of that accident was hushed up for a week.