Substandard explosives and unsafe production practices were to blame for a coal mine disaster in northern China's Shanxi province that killed 27 workers and left another seven trapped underground, work safety administrators said yesterday.

Rescuers descend into a mineshaft to at Anxin coalmine. [Photo: Xinhua]

"Substandard explosives stored in the shaft ignited, resulting in the deadly blast," an unidentified official with the provincial coal mine safety watchdog was quoted as saying by Xinhua News Agency.

The report said that inadequate safety at the mine was another reason for the heavy casualties.

"Investigations showed the mining company had exceeded its production quota, mined in unapproved areas and had poor ventilation facilities," Xinhua quoted Zhao Tiechui, director of the State Administration of Coal Mine Safety, as saying.

The explosion at 11?AM on Friday at the mine belonging to the Anxin Coal Mining Co occurred when 58 miners were underground. Fifteen people managed to escape, and another nine were rescued.

But according to safety rules, only 29 people are supposed to be working underground at any given time, Xinhua said.

The search for the remaining seven miners was halted on Saturday after rescuers found unused explosives and detonators in the shaft, the report said.

Other difficulties facing rescuers included a high density of toxic gas and the collapse of certain areas under the mine.

Wang Jun, director of the State Administration of Work Safety and Zhang Baoshun, Shanxi's Party secretary, arrived in Xiaoyi on Saturday morning to direct the rescue efforts.

Wang said a team would be set up to investigate whether the mine met safety requirements and determine the source of the explosives.

Police detained four people - the mine's chief and legal representative Tian Yun, a deputy chief and two workers in charge of blasting operations, according to Ren Fengding, a Xiaoyi city public security bureau official.

Seventeen others, including the city's coal mine administration personnel stationed in the mine, are being investigated by police, Ren said. Police are seeking a contractor, Wang Xiaoguo, who fled after the blast.

The coal company reported to local authorities that blasting activity under the mine's main shaft caused the incident.

The mine was approved to produce 90,000 tons of coal a year. It was permitted to resume production on May 18 after a regular safety check.

In another development, seven miners were confirmed dead and one was missing in a flooded colliery in the province, local authorities said yesterday.

The flooding occurred in Yutian Coal Mining Co Ltd in Ningwu County at 11?PM on Friday when 14 miners were working underground, according to the provincial work safety watchdog.

Five managed to escape, while one was rescued and sent to a local hospital, officials said.

(China Daily June 16, 2008)