A coal mine was flooded in Yuzhou City, central China's Henan Province early this morning, leaving about 20 people trapped underground, local authorities said.

More than 50 miners were working in the shaft when the accident happened at the Fushun Coal Mine at Yuzhou's Changzhuang Township,and about 30 of them managed to escape, said a spokesman with the municipal government of Xuchang, which administers Yuzhou.

A rescue operation was underway for the trapped, he said.

The coal mine is owned by the Hebi Coal Industry (Group) Co. Ltd. based in Henan's Hebi City.