More than 40 workers were poisoned in a hydrochloric acid leak in a south China factory, local authorities said on Sunday.

The accident occurred at 9 a.m. on Saturday at Quannao electrical appliance factory in Bao'an District, of Shenzhen city, where a 3,000-litre hydrochloric acid tank exploded as workers were filling it. Thousands of workers in nearby factories were evacuated.

More than 40 workers were poisoned by the chlorine and suffered pain in the abdomen and throat, and were sent to hospital.

One person was in critical condition while the others were stable, officials said.

The company needed hydrochloric acid to clear circuit boards, officials said.

Cause of the blast is being investigated.

(Xinhua News Agency June 9, 2008)