The dynamite, stored illegally in a coal mine owner's house in Puxian county, Shanxi province, buried the children and some of their teachers at the nearby school, the Beijing News said.

The mine owner was also killed in the blast, the Beijing News said.

Explosives or fireworks manufactured and stored illegally kill hundreds each year in China's rural areas.

Six thousand miners died last year in accidents and explosions that made the industry the world's deadliest and forced work-place safety on to the agenda at the annual session of parliament which starts on Saturday.

An official with the county government in coal-rich Puxian said many private coal mine owners possessed large quantities of explosives.

"But it is illegal to keep the explosives at home," he said.

Local police said they were unable to give further details.

The New York-based rights group, Human Rights in China, reported another grisly breach of work-place safety in northern Hebei province where five child factory workers died from asphyxiation caused by a charcoal heater, two apparently inside coffins.

"Due to the substandard conditions in the factory dormitory, five girls were found unconscious from inhaling charcoal fumes at the end of last year," the group said in a statement.

"Sources say that without checking if the girls were actually dead, (the factory owner) put them into coffins for cremation, with the result that two of the girls who were apparently still alive died of asphyxiation."