The warehouse of a building materials market caught fire early Wednesday morning in south China's Guangxi Zhuang autonomous region, leaving three dead, police said.

The accident occurred at 5 am at the building materials market at Xiu'an Road in Xixiangtang district in the region's capital city of Nanning, said a police officer with the city's public security bureau.

Three workers were pulled out of the fire and later died in hospital, the police officer said.

The fire, which spread over an area of 500 square meters, was put out by 7:30 am, and the cause of the accident is being investigated, he said.