By Mahmut Atanur

BEIJING

At least one person has been killed while 19 others remain trapped after an explosion at a coal mine in China's northwest Ningxia Hui Autonomous Region

State news agency Xinhua reported Tuesday that the blast, believed to have been caused by gas, occurred at a mine operated by Linli Coal Mining Co. Ltd. in Shizuishan City.

Rescue efforts remain ongoing.

Chinese mines are among some of the most dangerous in the world due to lax regulations and poor operating procedures.

In recent years, the country has produced more than one-third of the world's annual coal output, but accounted for more than two-thirds of global mining deaths annually, according to Mining Technology.

In January, 11 workers were killed after a coal mine collapsed in northwest Shan Xi province, while in February a gas leak at a coal mine in northeast Jilin Province left 12 miners dead.

In March, 19 people died after a coal mine collapsed in northern Shanxi province while 129 workers were working underground.