TAIYUAN - China has developed its first system designed to provide early warning of dangers in coal mines, the National Science and Technology Department announced on Thursday.

After passing expert review, it has now been put into operation in three mines in North China's Shanxi province, the country's second-largest coal producer.

The system provides all-day data and gives four levels of warning, according to Song Jiancheng, head of the research team.

Scores of sensors, deployed underground, collect data on factors including temperature and gas density which can be used to predict the likelihood of floods, explosions and other dangers.

The information is transmitted to a control center above ground for processing and production of reports.

China tops the world for coal production. However, frequent accidents have aroused safety concerns both at home and abroad.

As a result, China has issued a national outline to enlist the help of pre-warning technology in ensuring public safety before 2020.

The system will dramatically cut the risk of accidents for coal miners, according to Song.

"But it requires further improvement to have clearer analysis before it is applied in other coal mines nationwide," he added.