The death toll of a fatal coal mine explosion in northwest China's Ningxia Hui Autonomous Region has risen to 18, local authorities said.

According to an initial investigation, the explosion was caused by "illegal mining", local media reported Wednesday. The explosion occurred Tuesday at a small coal mine, which belongs to Linli Coal Mining Co. Ltd. in Shizuishan City. Twenty miners were working under ground at the time of the incident, state news agency (Xinhua) reported. 

One miner died after he was rescued from the shaft, the bodies of 17 more miners were also brought above ground. Two remain missing. More than 200 rescuers have been mobilized. 

The mine's annual production capacity is 450,000 tones. Its certificate remains valid until September next year. Most of the miners were from the provinces of Sichuan and Gansu, as well as Ningxia autonomous region. 

Source:  QNA