This undated photo shows a section of an ancient wall in the city of Datong, once a leading city of China in air pollution in 2013. The return of blue sky to Datong is due to years of strenuous efforts to cut emission and add greenery. (CAO YANG / XINHUA)

BEIJING – Most Chinese cities saw improvements in air quality in April, according to the Ministry of Ecology and Environment.

Some 337 cities enjoyed good air quality on 88.8 percent of days in April, up 7 percentage points from a year earlier. 

The average PM2.5 density, a key indicator of air pollution, fell 5.9 percent year on year to 32 micrograms per cubic meter last month.

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The ministry said in the first four months, cities saw an average of 79.9 percent of days with good air quality, an increase of 1.9 percentage points from the same period last year.

In the Beijing-Tianjin-Hebei cluster, the ratio of days with good air quality rose to 65.6 percent last month, compared with 53.7 percent registered a year earlier.

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This came as the country pledged to coordinate its efforts on environmental protection and economic development in 2019.

The country vowed to reduce imports of solid waste and push for better air quality with better regional coordination and heavy-polluter revamps, according to the ministry.