SHIJIAZHUANG, July 12 -- Another nine people have been confirmed dead after an illegal firecracker warehouse exploded in north China's Hebei Province, bringing the death toll to 15 as of Sunday night, the local government said.

The accident occurred at about 9 a.m. on Sunday in Dongwang Township, Ningjin County.

The explosion injured more than a dozen of others. Bloodstains have been spotted at the gate of a nearby garment factor.

The fatal explosion shattered nearly all the glass windows at a residential building close to the factory. A flour factory located about one kilometer away from the warehouse also had its windows broken.

As of about 6 p.m., heavy rescue machines were still entering the scene.

Investigators are looking into the cause of the explosion, the Ningjin government said.