A woman rides a bike amid dense smog in Baoding, Hebei Province. [File photo]

Six cities in Hebei Province made the top 10 in the ranking of 74 major cities in terms of the severity of air pollution in February, with Baoding ranked first, the environment watchdog said on Tuesday.

The consumption of coal for heating and setting off fireworks during the Spring Festival holiday were the major reasons for the increased smog in the top 10 cities, all located in northern China, according to the monthly report released by the Ministry of Environmental Protection.

The 13 cities in the Beijing-Tianjin-Hebei region witnessed a deterioration in air quality due to the fireworks, and the windless weather meant the pollutants could not be dispersed quickly, the report said, adding that these cities failed to reach the national standard on 17 days during February.

But the reported added that the majority of cities had seen a decline in the influence of fireworks on pollution compared to last year.

In response to the severe air pollution of Beijing-Tianjin-Hebei region last month, and the high probability of smog due to the windless weather forecast in the rest of March, polluters in the region will come under stricter supervision this month.

The ministry will send 10 teams to monitor the emissions in key areas of the trilateral zone. The teams will go directly to companies in polluting industries and make random checks. Use will also be made of data from remote sensing satellites and unmanned drones.

Those companies found making illegal emissions will face tougher punishments in a bid to deter all polluters, the ministry said.

Top 10 Chinese cities with worst air quality in Feb.

10. Handan, Hebei Province

Handan, Hebei Province. [File photo/Xinhua]