JINAN, Jan. 31  -- Two people were killed and four others were injured after a factory explosion in east China's Shandong Province Saturday, local authorities said.

The blast happened during an equipment overhaul in a plant of the Yehua Coking Co. Ltd. in Luozhuang District of Linyi City around 7:55 a.m. Two people died on the spot and the four injured have been sent to hospital, according to the local government of the district.

The cause of the accident in under investigation.