LIAOYANG, Liaoning -- Rescuers are still searching for the 17 miners who were trapped in a coal mine gas blast Thursday in Northeast China's Liaoning province, the rescue headquarters said.

By Sunday, more than 30 rescuers had gone to the shaft for more than 200 times, putting out the fire, setting up ventilating fans and digging to find the trapped, said a spokesman with rescue headquarters on the scene.

Seven experts were organized to give rescue instructions, and 50 medical personnel and 10 ambulances were waiting on the scene, said the spokesman.

Concentration of carbon monoxide and gas has hampered rescue efforts, he said.

The trapped miners are believed to have gathered at a work platform located 169 meters underground, according to the headquarters earlier on Friday.

The accident occurred at the Dahuang No 2 Coal Mine in the city of Liaoyang on Thursday, killing at least five people and trapping 17 others. A total of 23 miners were working underground at the time of the tragedy. One of them managed to escape.

The mine owner and other three relevant managers of the mine have been detained.

The cause of the accident is under investigation.