Taiyuan -- Rescuers said they had nearly finished search and rescue operations in a coal mine in north China's Shanxi Province, and confirmed a total of 104 bodies had been recovered from the pit by Friday, fewer than the total of 105 which they had feared.
The gas explosion happened at 11:15 pm Wednesday inside the Xinyao Coal Mine, a village-run coal mining venture in Hongtong County, Linfen City.
Police have detained 33 people who are alleged to be relevant to or responsible for the fatal gas explosion, said Wang Qingxian, a spokesman with the provincial government.
China's Ministry of Public Security on Friday issued a class-B arrest warrant for the owner of the mine.
The latest information on survivors was that 15 workers either escaped or were rescued later.
The official cause of the accident has yet to be confirmed but preliminary investigations cite a coal dust explosion as the root cause, according to Xu Zhancheng, engineer-in-chief with the Shanxi Provincial Bureau of Coal Mine Safety.
More than 120 rescuers from 13 crews are participating in the rescue operation. They have finished the rescue operation at the No. 2 coal seam, and are carrying out rescue efforts at the No. 9 coal seam. The vertical distance between the two coal seams is 30 meters.
"Xinyao is a low-gas coal mining pit," said Xu, "I think the explosion first happened at the coal seam No. 9 and later spread, affecting coal seam No. 2."
There was a delay of about six hours in reporting the explosion to the local authorities, who were not contacted until 5:00 a.m. Thursday. The authorities said they believed the colliery managers delayed reporting the accident while they tried to begin their own rescue operations, which meant that crucial time passed and casualties probably increased as many rescuers were among the dead.
Xinyao, owned by Ruizhiyuan Mining Co., held full, valid licenses at the time of the accident that allowed it to produce 210,000 tons of coal annually.
Rescue and recovery work was continuing on Friday morning and officials were seeking to identify the dead. Many of the victims were residents of Hongtong and others came from Hebei and Sichuan provinces and Chongqing Municipality.
The density of carbon monoxide with the No. 9 coal seam is said to have hindered access, further thwarting the rescue efforts. The rescue headquarters have worked out measures for ventilation to guarantee safety of the rescuers while the rescue operation continues.
Authorities including Li Yizhong, head of the State Administration of Work Safety, and Zhang Baoshun, Party secretary of the Shanxi Provincial Committee of the Communist Party of China (CPC), on Thursday rushed to the site of the accident. They called for "all-out efforts" be made to save those trapped inside the shaft.
Among those detained are the mine's manager Gao Jianmin and its legal representative. Wang Hongliang. The mine licenses have been sealed and bank accounts frozen.
The accident is the nation's second deadliest mining disaster so far this year. In August, 181 miners died when heavy rains flooded two mines in eastern Shandong province.