A ship carrying 100 tonnes of hydrochloric acid sank in China's Yangtze river Sunday after colliding with another vessel, state media reported, citing local officials.

The collision happened during strong winds in central Hubei province, Xinhua news agency said, adding that efforts were under way to retrieve the highly corrosive cargo.

The report did not say if the acid was contained on the sunken ship or had leeched into the water.

However, it cited officials from the Hubei Provincial Environmental Protection Department as saying tests on the water revealed a pH of betwen 7.5 and 8.0, which it said was within the normal range.

A reading of pH 7.5 is neutral, with figures higher than that indicating alkalinity while those lower indicate acidity.

Crew members were rescued from the vessel and local authorities estimated the operation to recover the chemicals would be completed Monday morning, according to Xinhua.

Industrial accidents are not uncommon in China, where an emphasis on economic growth has lead to widespread disregard for standards.