By Michael Bristow
BBC News, Beijing
Safety standards are meant to be better in China's state-run mines
China's leaders say they are making the country's coal mines safer places to work by closing small and illegal mines.
They claim that this campaign has reduced the number of coalmine deaths by nearly a half over the last four years.
But this latest accident near the city of Hegang in Heilongjiang province, where at least 87 people are known to have died, will remind them that the nation's collieries remain dangerous workplaces.
And the fact that Saturday's accident happened in a state-run mine - where safety standards are supposed to be better - will be a further worry.
The reaction from China's central government shows just how concerned it is about this latest mine explosion.
Just a few hours after the blast, China's state-run news agency Xinhua carried a report saying that President Hu Jintao and Premier Wen Jiabao had sent instructions to the rescue workers.
Vice-Premier Zhang Dejiang was sent to the scene of the accident, near the border with Russia, to help with the rescue efforts.
Officials need to be seen to be doing something because they know that the public is angry about the number of work-related deaths in China.
"Those who escaped this tragedy will have to go down again to work," commented one internet user on the Hegang accident.
"What happens next time or the time after that? Will they continue to be lucky?"
No easy task
The governor of Heilongjiang, Li Zhanshu, put into words what many people must have been thinking when they heard about the accident.
CHINA'S WORST MINE DISASTERS
Feb 1950: Yiluo mine, Henan province - 174 dead
May 1960: Laobaidong mine, Shanxi province - 684 dead
Sept 2000: Muchonggou mine, Guizhou province - 162 dead
Nov 2004: Chenjiashan mine, Shaanxi province - 166 dead
Feb 2005: Sunjiawan mine, Liaoning province - 210 dead
Nov 2005: Dongfeng mine, Heilongjiang - 171 dead
Aug 2007: Xintai City, Shandong province - 181 dead
Dec 2007: Rui Zhiyuan mine, Shanxi province - 105 dead
"We must put safety first," he said in comments reported by Xinhua.
"Development is important, but the growth of GDP shouldn't be achieved at the price of miners' blood."
China says work safety has improved, leading to a reduction in the number of deaths from accidents.
At a conference on mine safety in Beijing last month, the head of China's State Administration of Coalmine Safety, Zhao Tiechui, said mine accidents had fallen by 46.7% between 2004 and 2008.
But the number of deaths is still high: more than 3,000 workers died in Chinese mines last year - and nearly 100,000 died in all kinds of work-related accidents.
Ensuring every mine in China is safe will not be an easy task.
The government has concentrated its efforts on closing down smaller mines, which are often illegal.
That campaign started in 2005, but official figures released earlier this year reveal that illegal mines still account for four out of five of China's 16,000 collieries.
The problem is that China wants ever more energy to fuel its economic growth - and coal is the main source.
That puts pressure on local authorities to maintain production by turning a blind eye to safety standards.
Rescuers are still searching the pit for the missing miners
High demand also means there are vast profits to be made; the main street of the coal city of Linfen, in Shanxi Province, is lined with diamond shops, a testament to the spending power of mine owners.
These mine owners are often protected by corrupt local officials, making it more difficult to supervise collieries.
But perhaps what will worry the central government most about the Hegang accident is that it did not happen in a small illegal mine, but in a large state-run colliery.
If safety standards cannot be guaranteed there, what chance is there of enforcing them elsewhere?