The Ministry of Environmental Protection summoned top officials from seven districts in Beijing, Tianjin and cities in Hebei and Shanxi provinces over the weekend to reprimand them for their poor performance in controlling air pollution this year.

All of the local leaders acknowledged the problems and signed commitment letters with the ministry, promising to submit rectification plans within 20 days.

Air quality deteriorated in the seven districts and cities in the first quarter of this year, according to the ministry, and levels of major air pollutants rebounded. A monthlong inspection by the ministry also found severe violations of regulations in these regions, such as the poor implementation of restrictions during smoggy days, Liu Changgen, head of the ministry's Environment Inspection Department, said on Saturday.

One of the jurisdictions singled out was Tianjin's Beichen district, where the concentration of PM2.5－particulate matter of 2.5 micrometers or less that is hazardous to health－had risen by 36.5 percent year-on-year as of March 26, making it the city's most air-polluted district.

In Zhaoxian county, Shijiazhuang, Hebei province, PM2.5 levels had risen by 66.7 percent year-on-year as of March 26, seriously lowering headway the city had made against air pollution, Liu said.

The other five local governments were Beijing's Daxing district; Hejin in Shanxi; Kaiping district in Tangshan, Hebei; Yongnian district in Handan, Hebei; and Shenzhou, Hebei.

The seven cities and districts were found to have problems like companies excessively discharging pollutants and poor implementation of countermeasures, the ministry said.

In Shenzhou, the departments that oversee urban construction and development in an industrial zone ignored the task of reducing dust at construction sites.

All of the seven local governments' leaders admitted the shortcomings in their jurisdictions exposed by the inspections.

Gao Nan, head of Zhaoxian county, said that he felt very guilty to see the increased air pollution.

"The deteriorated air quality shows we did not work as required, and some departments did not cooperate, especially in dust control," Gao said.

The county will invest 1.3 billion yuan ($189 million) to build a road that will keep high-exhaust diesel vehicles away from the downtown areas, he said.

The reprimands were conducted to hold city and county level governments accountable for their poor performance in reducing air pollution and to bring about change.

From Feb 15 until March 18, the ministry had more than 260 inspectors checking air pollution control efforts in Beijing, Tianjin and the provinces of Hebei, Shanxi, Shandong and Henan.

Of the 8,500 firms and government departments inspected, problems were found in 3,000－including falsification of data in a large number of them－according to results the ministry released on Friday.

Following up on the monthlong inspections, the ministry intends to conduct random inspections in April to guarantee that air pollution restrictions will be observed.