At least 25 miners were confirmed dead in the explosion in northwest China's Shaanxi province, while another 127 miners, who were working underground when the explosion took place in the state-owned Chenjiashan coal mine, managed to escape.
There were 293 miners working underground when the accident occurred at 7:20 am (4:50 am IST) in coal pits some 8,000 meters away from the entrance.
Those who escaped were mainly workers near the entrance, who suffered from carbon monoxide poisoning or minor injuries. All the injured, including 11 who are seriously wounded, have been hospitalised, Xinhua news agency quoted officials from the rescue headquarters as saying.
Rescue work was hampered initially due to the thick concentration of carbon monoxide in the air, which has exceeded the safety standards.
A rescued worker said even though he was stationed approximately 1500 metres from the blast site, he was knocked down by the strong airflow caused by the explosion.
The priority task was to resume ventilation which had been greatly damaged in the explosion, and to guarantee the rescuers' safety, deputy head of the State Production Safety Bureau, Zhao Tiechui Zhao said.
Six rescue teams are taking part in the salvation operation and the provincial government has ordered all the mines with high gas concentration to halt operation for safety examination, the report said.
China's top leadership has expressed great concern over the mine disaster. President Hu Jintao and Premier Wen Jiabao have asked local officials to "try every possible means to search for the missing, take care of the injured and handle well the aftermath," a report said.
Senior provincial officials, including Li Jianguo, secretary of the Shaanxi Provincial Committee of the Communist Party of China (CPC), and Chen Deming, acting governor of Shaanxi, have all rushed to the site of the accident to coordinate the rescue operation.
The Chenjiashan Coalmine is a state-owned venture under the jurisdiction of the Tongchuan Mining Administration capable of producing 2.3 million tonnes of coal a year. A gas explosion had killed 38 in this mine in April 2001.
This is the second major gas outburst disaster in the past 40 days to hit China. A gas explosion occured at the Daping Coalmine in central China's Henan Province on October 20, killing 148 and injuring 32.
16 killed in mine blast in China
In another development, the Government has said it will prosecute 16 officials of Handan County in north China's Hebei Province on charges of covering up a major coalmine blast in June.
The gas explosion took place at the Hongda Colliery on June 3 this year, killing 14 miners and injuring 23 and caused losses of 2.07 million yuan (249,400 US dollars).
But, the coalmine owner, who feared that reporting the real number of casualties would lead to it being shut down, connived with some local officials to cover up the death toll, telling investigators that only one person died.
