At least two people have been detained in connection with an explosion at a metal factory in China's Jiangsu province that claimed the lives of 68 people and injured 187 others.There were 264 people at the site when the explosion hit the wheel hub polishing workshop owned by the Taiwanese-invested Kunshan Zhongrong Metal company in Kunshan city Saturday morning, Xinhua reported.Kunshan is a small city located outside of Suzhou in Jiangsu province of eastern China.Kunshan Zhongrong's two senior executives have been placed under police custody, sources said.Officials have said the explosion was a work safety accident, and the blast was probably caused by flames igniting dust inside the workshop. Among the dead, 44 were killed on the spot, while 24 died after medical treatment failed. Most of the injured have been transferred to hospitals in nearby cities of Suzhou, Wuxi, Nantong and Shanghai.