Police said Thursday they have put 11 people in custody in connection with a chemical blast that killed 18 in east China's Shandong Province.

Investigation showed that Yunheng Logistics Service Center of Shandong Jinlan Modern Logistics Development Co. in Linyi City had no operation license and illegally stored and transported dangerous chemicals.

The 11 people are executives from the Yunheng Logistics, Linyi Xuehua Trade Company and Yixing Yuanheng Logistics Company in neighboring Jiangsu Province.

The explosion occurred on September 2 as workers from the Yunheng Logistics were unloading a lacquer-curing agent from a truck at Jinlan Logistics Town in Lanshan District, Linyi.

Seven people died at the scene and 11 others died of injuries in hospital. Of those 14 were women.

Ten more were slightly injured.

The main ingredients in the agent are xylene and butyl acetate, both inflammable and poisonous.

(Xinhua News Agency September 11, 2009)