BEIJING, March 19 (Xinhua) -- The Ministry of Environmental Protection said on Sunday it has found more irregularities harming China's environment protection efforts during its 4-day inspections ended Saturday.

The 202 irregularities, including unauthorized restarting of production despite a government ban and non-compliance with emission reduction measures, were discovered by 18 inspection teams dispatched to Beijing,Tianjin and 16 other cities by the ministry.

The inspection teams called for local governments and relevant companies to investigate and rectify the situation as soon as possible.

Beijing issued a blue alert for heavy air pollution Sunday morning.

The alert is forecast to last one day and people should take precautions and reduce outdoor activity, said a statement issued by the city's air pollution emergency response office.

At 10 a.m., readings at most of the city's monitoring stations for the hazardous fine particle matter PM2.5 exceeded 250 micrograms per cubic meter, according to Beijing Municipal Environmental Monitoring Center.

Air quality should improve by Monday noon, the center said.

Beijing has a four-tier alert system for pollution, with red being the highest, followed by orange, yellow and blue.