Toll rises to 23 in southern China mining accident
A carbon monoxide leak on Friday evening at the Diaoshuidong mine in the city of Chongqing left 18 miners confirmed dead the next day as rescue efforts continued.
But state media said Sunday that the toll had risen to 23 with only one survivor.
Xinhua added that investigators were working to determine the cause of the tragedy.
An earlier accident at the same mine claimed the lives of three people in 2013, according to Xinhua.
Sixteen workers were killed at another mine on the outskirts of Chongqing in September after a conveyor belt caught fire and the blaze produced dangerous levels of carbon monoxide.