Excessive concentration of dust that met a fire source has been confirmed to cause last Saturday's explosion that killed 75 people and injured 185 in Kunshan in neighboring Jiangsu Province, Xinhua News Agency reported Monday.

The explosion has been labeled as "serious" by the investigation team of the State Council. The team is led by Yang Dongliang, director of the State Administration of Work Safety.

The investigation team said the main person liable for the explosion included Wu Jitao, chairman of Zhongrong Metal Products Co Ltd where the blast happened.

It said local government failed to meet their responsibilities and did poor in supervising the company.