Residents wearing masks participate in outdoor activities on Lincui Road in Beijing on Saturday. The Beijing Meteorological Bureau issued a blue warning for a coming storm that was expected to increase dust levels. WANG JING/CHINA DAILY

The national environmental watchdog is flexing its muscles in implementing the toughest law on environmental protection since the new minister took office.

Four city governments with serious pollution have been invited in the past two months to talk about their supervisory activities.

The top leaders of the four cities admitted that serious pollution existed and promised to take swift and tough measures to solve the problem during the talks, which were a direct way for the central authorities to urge lower departments to redouble their efforts.

The latest talk was with the Zhumadian city government in Henan province on Wednesday.

The city's environmental protection bureau said it asked the Pingyu county government three times to shut down 27 illegal leather factories, which had heavily polluted their surroundings.

But the county government acted slowly, and the number of illegally polluting companies increased to 30 in February.

The Ministry of Environmental Protection asked the deputy mayor of Zhumadian to ask the city government to order the county government to close the polluting companies and hold their leaders accountable.

Four days after the talks, the city announced that four leaders in charge of environmental protection had been suspended from their positions, and the polluting companies were shut down.