Seven officials in charge of coal mine safety in Shanxi have been indicted and sentenced this year, providing clues as to why there are so many deadly coal mine accidents in the province.

Those county-level safety supervision bureau chiefs have taken a huge amount in bribes from mine owners and acted as shields for their illegal business activities.

The North China province is the largest coal producer in the country, accounting for about 30 per cent of national coal production.

Li Yizhong, minister of the General Administration of Work Safety, has pointed to widespread corruption in the management of the highly lucrative industry as one of the major causes of the accidents.

Just last year, 3,341 coal mine accidents killed some 5,986 people in the country. The accidents' causes were diverse; complicated geological conditions in some places, inadequate safety input, faulty underground operation and loose daily management provide some answers to the question.

People have also long suspected officials' involvement in those illegally operated coal mines, many of which obviously cannot meet safety standards but are licensed nonetheless.

In a sense, the most dangerous are not those without safety licences, but those that are licensed yet still cannot meet safety requirements.

The new development in Shanxi solves the puzzle of why large-scale accidents keep cropping up in local mines despite strengthened central measures.

Loose management can be improved if local officials become more alert and are made to abide by relevant supervisory procedures. But intentional cover-ups would be a much more thorny knot to untangle, especially when it becomes rampant and driven by economic interest.

The Shanxi case raises the question of how to uncover such cover-ups, or, in other words, how to put safety supervision officials under effective supervision.

Given the many loose licence approval cases in the mining sector found in various investigations, it becomes common sense that the safety situation would be greatly eased if the local officials in charge of safety production could be closely watched to prevent their abuse of power.

It is obvious that the current supervision mechanism remains porous.

Power may be easily abused without a strong external supervisory force. This is one of the lessons from the Shanxi cases.

And we may find better solutions to coal mine accidents if we give serious attention to the matter.