BEIJING, Aug. 27 (Xinhua) -- China's safety watchdog on Monday released the results of investigations into the molten aluminium spill in east China's Shandong Province which killed 16 people and called for intensified supervision in the metallurgy and non-ferrous metal industries to prevent such fatal accidents.

According to the circular released by the State Administration of Work Safety, the container of molten aluminium was designed by unqualified Shangdong Weiqiao Aluminium Electricity Co. Ltd. with "serious defects".

The factory was also responsible for the accident because it failed to establish the product lines in accordance with the original design and evacuate workers on the scene in time, said the circular.

The safety watchdog required enterprises engaged in relevant industries to hire qualified designers for their projects and arrange construction in strict accordance with plans.

These enterprises should organize special investigations to find hidden trouble in the work place and supervise the entire production process, said the circular.

On August 19, the accident occurred as workers gathered for a morning meeting in an aluminium plant affiliated to the Weiqiao Pioneering Group Co., Ltd. in Zouping. It killed 16 people and injured 59 with a direct economic loss estimated to reach over 6.6million yuan (about 860,000 U.S. dollars).