More than 1,000 containers containing explosive chemicals were washed into a major river in northeast China's Jilin Province Wednesday, and 350 of them have been recovered, local authorities said late Wednesday night.

Residents stand along a bank of the Songhua River on Wednesday in Jilin province, where more than 1,000 barrels containing explosive chemicals surfaced after being dislodged by the flood. [China Daily]

The accident occurred around 10 a.m. in Yongji County, in Jilin City, after rain-triggered flood water swept the containers into the Songhuajiang River, according to the publicity department of Jilin City Committee of the Communist Party of China.

Some of the containers, from a local chemical plant, each contained 160 kg of trimethyl chloro silicane, a colorless flammable liquid with a pungent odor, said the department.

The chemical would give off hydrochloric acid after reacting with water, said experts.

Emergency workers have set up blocking belts and recovered more than 350 containers, said a spokesman with the emergency response office of the municipal government.

Torrential rains began pounding Yongji County Tuesday evening and brought about a flood crest which swept the chemical plant.

A Xinhua reporter in downtown Jilin City saw dozens of containers floating on the river and a "strange" odor could be smelled.

With a population of 4.5 million, Jilin City is the second largest city of Jilin Province, after the capital Changchun.

"I saw a large number of iron containers, blue or black in color, floating on the river along with much rubbish," a policeman who patrolled along a section of the river in Jilin City told Xinhua in a phone interview. He asked not to be identified.

A resident surnamed Xu in Changyi District, Jilin City, said the water supply of his community had been turned off and bottled drinking water in nearby supermarkets had been nearly sold out.

The 1,900-km Songhuajiang River is the largest tributary of the Heilongjiang River, a border river between China and Russia.

The Songhuajiang River was contaminated by a chemical spill after an strong explosion at a petrochemical plant in November 2005, which resulted in a five-day cut of water supplies to the 3.8 million residents of Harbin, capital of Heilongjiang Province.

By midnight emergency workers were still trying to recover the containers and local environmental protection authorities have established seven monitoring locations to inspect the water quality in the river.

The monitoring results have shown the pH reading in the river water remains within the normal range, said a spokesman with the provincial environmental protection department.

But "a very small quantity" of two pollutants, both chemicals produced in the plant, were found in the water, said the spokesman, without clarifying the strength of these chemicals.

"We will respond immediately if any contamination is discovered. We haven't received such reports from the upper stream," said Chi Xiaode, director with the environmental supervision bureau in neighboring Heilongjiang Province, located further downstream.

The news had aroused panic purchase of packaged drinking water in some cities along the river.

At an outlet of Darunfa Supermarket in Harbin, bottled drinking water were sold out within half an hour on Wednesday evening, a Xinhua reporter said.