Fourteen workers were killed and five more injured Saturday in a chemical plant explosion in east China's Shandong Province, local authorities said.

The explosion occurred at about 2 pm at a melamine production facility of Shandong Liaherd Chemical Industry Co., Ltd. in the city of Xintai when workers were maintaining and repairing a condenser, the Xintai city government said in a statement late Saturday.

Four workers were killed and further 15 injured at the scene. But 10 injured died later at hospital after emergency medical treatment failed, raising the death toll to 14. The remaining five injured were in stable conditions, according to the statement.

An investigation into the cause of the accident is underway.