At least nine people were killed in a coal mine accident in north China's Shanxi Province which was concealed by the mine managers for nearly a month, local authorities said on Monday.

The Liziping Coal Mine, in Xiangning County, Linfen City, was flooded on July 5, but managers failed to inform the work safety authorities, a spokesman with the Shanxi Provincial Work Safety Administration said.

The administration learned of the accident after an anonymous tip off and immediately started an investigation into the accident, he said.

A working team was set up on Monday to investigate those who covered up the accident, he said.

(Xinhua News Agency July 31, 2007)