The accident occurred early Saturday morning in a pit owned by Pingyu Coal & Electric Co Ltd based in Yuzhou city, although 239 people escaped.
The remaining 11 are probably buried in coal dust and unlikely to be alive, the official China Daily said.
Another gas leak in 2008 at the same mine killed 23 people, the report added.
The accident occurred after Chile’s dramatic rescue of 33 miners trapped for more than two months underground.
China’s mines are the deadliest in the world, due to lax safety standards and a rush to feed demand from a robust economy. More than 2,600 people died in coal mine accidents in 2009 alone. Reuters