Northeast China's Liaoning Province has started to use drones with remote sensing systems to battle air pollution, a local environment watchdog said on Monday.

Northeast China usually sees a surge in the number of smoggy days in winter as a large amount of coal is burned to heat the region.

Since bad traffic and snowstorms disturb air quality checks, Liaoning will use drones to detect polluters and control smog.

The drones provide real-time inspection of the source of pollutants, said Wu Di, deputy director of the environmental inspection bureau in the city of Liaoyang, which is the first in the province to use drones in smog control.

Wu said the bureau can determine if a factory emits too many pollutants using two drones. "One drone will record the real-time ground image and send it back immediately to the command center. Another will then fly to areas which we think cause smog, and then analyze the air quality index of those areas at an altitude between 200 and 1,000 meters," Wu said.

Those violating the emission rules will be punished, Wu added.

Tianjin, a coastal city in north China, also uses remote sensing technologies to monitor car emissions.