Chinese state media say rescuers racing to save 19 trapped coal miners suspended their efforts Monday because of high levels of toxic gas.

The Xinhua news agency said the rescue command center at the Heshan mine in southern Guangxi province ordered rescuers to retreat when carbon monoxide and other gases spewed out of the shaft in the middle of the night.

The article said the mine collapsed Saturday. Forty-nine miners managed to escape.

Initial investigations indicate that the collapse was caused by continuous heavy rains.