China's official Xinhua News Agency says 18 miners are trapped after a coal mine blast in central China.

Xinhua said the blast happened in Lianyuan city in Hunan province and that rescuers are trying to contact the trapped miners.

It said 32 miners were working at the time of the blast but that 14 managed to escape.

The news agency said authorities have launched an investigation into the cause of the blast at the township-owned mine, which has an annual capacity of 30,000 tons.

China's coal mines are the world's deadliest, with fires, floods and other disasters killing an average of 13 miners a day.