An early morning factory fire left 15 people dead and three others severely wounded in Shenzhen, a state news agency reported Wednesday.

Xinhua News Agency said the fire in Shenzhen, a booming industrial city in Guangdong province, broke out several hours before dawn.

It said 15 were confirmed dead at the scene.

Firefighters rescued six from the building, but three others were taken to hospital with serious injuries. The cause of the fire is being investigated, Xinhua said.