BEIJING -?Minister of Environmental Protection Chen Jining Monday said that Chinese cities reported more "good air" days in 2016.

Last year, the 338 cities monitored by the ministry enjoyed good air quality on 78.8 percent of days, up 2.1 percentage points from 2015, said Chen at the bimonthly session of the National People's Congress Standing Committee.

Those cities reported heavy or even worse air pollution on 2.6 percent of days, down 0.6 percentage points, Chen said.

China received 33,000 tip-offs on environmental violations, issued fines worth 440 million yuan (64 million U.S. dollars) in 8,500 cases, and detained 720 people in more than 800 cases, he added.

Chen called for beefed up efforts to fight air, water, and soil pollution and fully implement action plans in such fields.

According to the minister, the State Council, China's Cabinet, last year approved the establishment of 18 national nature reserves and carried out remote monitoring of human activities in 446 national nature reserves.

Chen also stressed tightening nuclear and radiation safety supervision.

China has maintained good quality of the radiation environment through proper operation of its 35 running nuclear power units and 19 research reactors for civil use. The 21 nuclear power units under construction are being built according to plans.