At least nine miners died from carbon monoxide poisoning in a colliery in China's Henan province Sunday night, officials said Monday.

Rescuers had found bodies of three miners under the mine shaft, and later brought out six others and took them to hospital, where they succumbed, Liu Xianghua, deputy director of the Coal Mining Bureau in Yiyang City, was quoted as saying by Xinhua.

Safety staff with the mine, owned by the Dongsheng Mining Co. Ltd., detected excessive amounts of carbon monoxide in the mine Sunday night, when two miners were working underground. The company sent seven others to check the situation, but lost contact with them afterwards.