China launched its largest operation to control air pollution in northern regions on Wednesday, using more than 5,600 inspectors to push the areas to meet ambitious pollution reduction targets this year.

Unlike the nationwide inspections conducted last year, headed by the State Council, the yearlong, intensified inspection is being led by the Ministry of Environmental Protection.

The 5,600-plus inspectors will keep a spotlight on governments and companies in 28 major cities in the Beijing-Tianjin-Hebei region and the neighboring provinces of Henan, Shanxi and Shandong, which are susceptible to heavy smog, the ministry said.

Inspectors will check important areas like governments' implementation of air pollution control efforts, companies' emissions monitoring equipment and monitoring networks. They will also shut down small plants with high emissions, it added.

"Through the inspection, the ministry will push these governments and involved companies to fully implement measures to tackle the air pollution," Zhai Qing, vice-minister of environmental protection, said on Wednesday.

"We will keep eyes on the regions with pollution problems and stick with them until all the pollution issues that are exposed are solved," he said, adding the results should be released to the public.

During a separate, weeklong inspection that the ministry started on April 1 in the same northern regions, seven inspection teams have checked over 450 companies and government departments, finding at least 281 violations, including companies that falsified monitoring data or discharged excessive pollutants, ministry officials said.

Zhai said the inspection has worked to lower pollution.

"The minister and vice-ministers frequently have been seen leading inspections in northern regions, showing their focus on the issue," said Chang Jiwen, an expert in environmental policies with the State Council Development Research Center.

Though the inspection worked, he suggested it's more efficient and effective to motivate the cities and counties to better control pollution than high-level but short-lived inspections.

For the northern regions, where similar pollution problems were frequently found, the ministry should suspend approvals of environmental impact assessments for new projects－necessary before construction can begin－forcing corrective action by cities and counties before assessments in their jurisdiction can go forward, Chang said.

By the end of 2017, the Beijing-Tianjin-Hebei region should lower the concentration of PM2.5－fine particulate matter that is harmful to health－by 25 percent from the 2012 level, according to the Action Plan on Air Pollution Prevention and Control, released by the central government in 2013.

The PM2.5 concentration in Beijing should be cut to 60 micrograms per cubic meter this year, down from 73 last year, which officials and experts agree is a major challenge.

To meet the goals, the governments both in Beijing municipality and at the central government level have taken what experts call extra tough restrictions on pollutant emissions in the northern region, such as the annual regional pollution control plan released two weeks ago.

It requires cement and casting plants in the 28 cities to suspend production during the heating season from Nov 15 to March 15, though those providing heating services and processing dangerous waste are not included.