BEIJING -- China's Ministry of Environmental Protection (MEP) Friday criticized Changchun city in northeast China's Jilin Province for not doing enough to cope with air pollution.

In the first 10 months of this year, air quality in Changchun saw continuous degradation, with the amount of time with serious pollution increasing by 7 days compared to the same period last year, while days with good air quality decreased by 22, according to an MEP statement.

The inspectors found some of the city's air quality indicators were "extremely high" for a long period of time.

Changchun was criticized for outdoor straw burning and not implementing emergency responses strictly, the statement said.

Several companies in the city were also criticized by the ministry for breaching emission rules.

Additionally, 25 development zones in the city lagged behind in upgrading coal-fired boilers and some companies in the zones lacked desulfurization facilities.

The city should submit plans to address the problems to the inspectors within 20 working days, the ministry said.

China is intensifying efforts to fight pollution and environmental degradation after decades of growth left the country saddled with problems such as smog and contaminated soil.

A total of 6,471 officials in eight provincial-level regions were held accountable for environmental damage after inspections by central authorities from August to September.

Tackling pollution has been listed as one of "the three tough battles" that China aims to win in the next three years, according to the Central Economic Work Conference, which concluded earlier this week.