HARBIN, Aug. 14 -- Twenty-three people were still trapped after a coal mine was flooded in Jixi City, in northeast China's Heilongjiang Province, local authorities said.

The privately-owned Anzhishun Coal Mine previously reported that nine people were trapped following the flooding at 1:10 p.m. Thursday, but investigators later confirmed that 56 workers were down the shaft when the accident happened, and 33 of them were lifted to the ground, according to the public security bureau of Jixi.

Rescuers are installing pumps to drain the flooded shaft.

The mine's owner has been placed under police custody.