BEIJING: Two persons were killed and eight others injured today in a chemical factory blast in China's northwestern Xinjiang Uygur Autonomous Region.The regional work safety administration said the explosion took place at one of the calcium carbide furnaces of the Yihua chemical plant. The reason of the blast is yet to be ascertained.The explosion in the plant in Changji Hui Autonomous Prefecture left two persons dead and three in serious condition. Five persons sustained minor injuries.