The official news agency Xinhua said the miners had been trapped in the Yangquan City mine since Tuesday morning.
Rescuers had been working to lower the water level but a lack of geographical data had made it difficult.
The miners had illegally dug three pits below a small room in a residential courtyard. A local resident told Xinhua he learned that some people used farm vehicles to transport coal from the courtyard.
Rescue efforts and further investigation into the incident continue.