Photo taken on July 28, 2010 shows barrels containing explosive chemicals in the water of the Songhua River in Jilin City of northeast China's Jilin Province. [Xinhua]

About 3,000 barrels filled with chemicals have been swept into a major river in northeast China's Jilin Province, thousands more than originally thought, authorities said Thursday.

Another 4,000 empty barrels have also entered the river, officials said at a press conference Thursday morning.

On Wednesday, authorities said around 1,000 barrels had entered the Songhuajiang River in Jilin City.

Barrels were spotted in the river Wednesday, but it is not known when they entered the waterway.

The barrels first entered the Wende River and then flowed into the Songhuajiang River, after floods hit the storage facilities of two chemical factories -- Jilin Xinyaqiang Biochem Co. Ltd. and Jilin Zhongxin Group.

Each chemical-filled barrel contains about 170 kilograms of chemicals.

Of the 3,000 chemical-filled barrels, about 2,500 barrels contain trimethyl chloro silicane -- a colorless flammable liquid with a pungent odor -- while 500 contain hexamethyl disilazane -- a colorless liquid with a pungent odor.

Officials said emergency workers and soldiers are rushing to retrieve the barrels. Workers are collecting the barrels at eight points on the river. About 400 have been recovered so far.

Seven stations have been established to monitor water contamination.

Photo taken on July 28, 2010 shows barrels containing explosive chemicals in the water of the Songhua River in Jilin City of northeast China's Jilin Province. [Xinhua]

(Xinhua News Agency July 29, 2010)