A tank containing hydrochloric acid exploded at a factory in southeastern China, injuring more than 40 workers, Xinhua reported on Sunday.

The accident occurred early on Saturday at the Quannao electrical appliance factory in the Bao'an District of Shenzhen when workers were filling a 3,000-litre tank with the acid.

Thousands of workers in nearby factories were evacuated, according to the report, which cited local authorities.

More than 40 workers were hospitalised for abdomen and throat pains, including one who was in critical condition.

The cause of the accident was being investigated. The company uses hydrochloric acid to clear circuit boards, officials said.