Beijing  - An explosion in the dynamite warehouse of a coal mine killed at least 18 people in central China's Hunan province, state media reported Saturday.

Two people were missing after the blast destroyed the three-storey warehouse Friday in Yongxing County in Chenzhou city.

Police were investigating the cause of the blast and searching for three of the mine's shareholders, the official news agency Xinhua quoted Yongxing County head Xie Guanghui as saying.

But the report also said one of the shareholders had already been "put under control."

It was the second mining accident in as many months in Hunan.

In March, 13 workers died in a flooded mine that had been operating illegally.

The official number of coal-mining fatalities in 2008 was 3,215, a 20-per-cent decrease on the previous year, according to state media.

However, the actual figure could be much higher. China still has many illegal or "black" mines, and even legal mines routinely underreport fatalities to avoid suspension of work by authorities.

According to the State Administration of Work Safety, as many as 200 deaths were covered up in 2006. (dpa)