The Chinese government on Thursday released a coal industry policy document, putting a ban on new coal mines with an annual capacity below 300,000 tons.

   The document comes in the wake of a nationwide campaign to close down small coal mines, which account for one third of China's total production but two thirds of the deaths resulting from colliery accidents.

   But as existing small mines were being shut down, new ones were being opened, Li Yizhong, head of the State Administration of Work Safety, admitted earlier this year.

   The top work safety official said that the work safety situation remained grave because colliery accidents were still prominent.

   Last year, China produced 2.4 billion tons of coal but production of its 80,000 coal companies averaged only 30,000 tons. Meanwhile, accidents in small coal mines claimed 3,431 lives.

   To better protect the environment, the document said that environmental appraisal must be carried out in coal mines and that coal mines must not be built in such "vulnerable areas" as nature reserves, water sources and geological hazard zones.

   A total of 13 large coal production bases would be formed in Shanxi, Shaanxi, Shandong, Henan, Yunnan, Guizhou, Ningxia and Inner Mongolia to ensure stable supply of coal in the country, it said.

   The document also aims to protect the interests of coal mine workers, saying they should work in four shifts per day and be covered by work injury insurance.