China's mining industry is by far the world's deadliest, with accidents and blasts killing more than 2,600 coal miners last year, according to official figures. Independent labour groups say the actual figure could be much higher as many accidents are covered up to avoid costly mine shutdowns.

Zhao Tiechui, head of the State Administration of Coal Mine Safety, said in February that China, which relies on coal-generated power for about 70 per cent of its electricity needs, would need at least 10 years to "fundamentally improve" safety and reduce the frequency of such disasters.

Second major accident

Saturday's blast was the second major industrial accident to hit the country this week.

China's mining industry is the
world's deadliest [Reuters file]

On Wednesday, 13 people were killed by a powerful chemical pipeline explosion that rocked a city in eastern China.

More than 300 others were injured in the blast, which occurred on the grounds of an abandoned plastics factory in Nanjing, capital of Jiangsu province, as workers were demolishing the facility.

Meanwhile on Friday, civilians were mobilised to join exhausted soldiers and emergency workers struggling against mounting difficulties to retrieve thousands of chemical-filled barrels that were swept into a major northeast China river by flood waters this week.

Some 3,000 full barrels and 4,000 empty ones were swept into the Wende river and on to the Songhua river after floods hit warehouses of two chemical factories in Jilin City, in Jilin province, early on Wednesday.

By Friday evening, only about half of the 7,000 containers had been retrieved, according to the provincial government, which vowed to retrieve all the containers before they flow out of the Hadashan Reservoir on the lower reaches of Songhua river.

However, salvage workers fear some of the barrels, many filled with flammable liquid, may have sunk to the bottom of the Songhua river, raising serious risks of lingering water contamination.

Chemical barrels were also spotted lying unattended in the debris of flood-devastated villages.