China's state media says an explosion at an illegal fireworks factory in eastern China has killed 13 people.

The official Xinhua news agency says the blast occurred Saturday in the city of Weifang in Shandong province.  Officials told the media that an abandoned kiln exploded while being used illegally to produce fireworks.

Xinhua says the local government initially reported three fatalities, but the death toll rose after officials found ten more bodies in the factory Sunday.

China's huge fireworks industry is notorious for its lax safety standards.   

Some information for this report was provided by AFP, AP and Reuters.