BEIJING, Nov. 20 (Xinhua) -- China's work securities supervisor has urged local authorities to overhaul fireworks factories in a circular addressing an accident earlier this month.

The blast at a firecracker plant in central Hunan province on Nov. 10 killed 10 people and destroyed two workshops out of four at the plant.

Preliminary investigation found the cause of the accident to be highly dangerous, banned work procedures.

The circular instructed local authorities to check on malpractices in firecracker factories immediately. Such practices include gathering too many people in a workshop, loading excessive explosive powder and mixing highly dangerous procedures in low-level safety workshops.

Factories that are found to be breaking the rules must stop operating until their operations are approved by local authorities. Facilities that commit major violations could have their licenses revoked.