Seventeen people have been penalized over an explosion at a workshop that left 13 people dead and 15 others injured in east China's Zhejiang Province in August, the local work safety supervision department said Tuesday.

Jiang Qigong and Li Ruifang, the husband-and-wife team that owned the illegal workshop, and Lu Zheng, the owner of the building where the blast occurred, have been placed under investigation for criminal responsibilities, according to sources with the department.

Fourteen local officials, including the director of the district, have received punishments such as administrative warnings, demerit recordings and dismissal from their posts within the Communist Party of China, among other penalties.

The accident happened at a workshop specializing in polishing and processing hardware locks in Guonan Village in Wenzhou City's Ouhai District on Aug. 5, 2012. A fire burned in a 200-to-300-square-meter area after the explosion.

Investigators found that thick dust mostly made up of aluminum powder in the workshop was ignited by sparks from the polishing machine, triggering the explosion.