The death toll in Tuesday's liquefied chlorine leakage in Huai'an city in east China's Jiangsu Province has risen to 28, a local official said on Thursday.

Three of the 17 injured are in a critical state, Lu Changsu, vice-mayor in charge of public security of Huai'an city, said.

The leakage caused by a truck collision also poisoned 350 people, he added. Over 10,000 locals have been moved from the affected area.

The accident occurred when the tanker truck, carrying 35 tonnes of liquefied chlorine, went out of control due to a flat tire and rammed into a cargo truck on the Beijing-Shanghai expressway.

Both vehicles turned over and the cargo truck driver was killed on the spot. The tank driver fled from the scene, but later surrendered in Nanjing. He has been brought back to Huai'an for investigation.

Rescuers have dug a pond by the roadside, where they are neutralising the chloride with caustic soda. The process is estimated to last for two days, Xinhua news agency reported.