HEFEI - A colliery flood early Sunday morning in East China's Anhui province has left an unknown number of casualties, provincial coal mine safety authorities said.

The flooding occurred at 0:20 am, when about 400 miners were working underground at the Taoyuan Mine. Some miners have been rescued.

Rescuers are searching for the missing miners in the shaft operated by the Huaibei City-based Anhui Huaibei Mining Group, according to the Anhui Provincial Administration of Coal Mine Safety.

The exact number of the missing was still to be confirmed.