More than 110 companies in northeastern China that failed to reduce pollution will be severely penalized by the government, the national environmental watchdog said on Thursday.

Three of the companies failed to cut their production under the emergency response ordered after severe haze hit the region.

This was disclosed on Thursday by Zou Shoumin, head of the Environmental Inspection Bureau under the Ministry of Environmental Protection.

“We found that small and private companies had more problems than these three firms and that 15 companies out of the total failed to control air pollution emissions while providing heating services because they lacked facilities,” Zou said.

Another 100 small companies in Fushun, Liaoning province, were found to have discharged pollutants directly, worsening air quality, Zou said, adding that such heavy polluters will be severely penalized.

The ministry has carried out inspections in recent days in the three northeastern provincesļ¼¨Heilongjiang, Jilin and Liaoning, which have seen severe smog.

“The inspections will continue, with tougher penalties to deter polluters and improve air quality,” Zou said.

Air quality has improved in the three northeastern provinces since they tightened supervision on Saturday of major sources of pollution, such as industrial production and vehicle manufacturing.

As of 10 am on Thursday, the number of cities with severe air pollution had fallen to 12 from 24 on Saturday, the ministry said.

Luo Yi, head of the Environ-mental Monitoring Department at the ministry, said air pollution will continue for a day in the northeast before easing gradually from hazardous levels to a light level because of slight rainfall.

Residents of most areas in the three northeastern provinces may see good air quality by Tuesday, Luo said.

In addition to the north-east, many cities in northern China, including Beijing and Tianjin, have been blanketed by severe smog for three days.

Beijing saw readings of PM2.5 reach 230 micrograms per cubic meter as of 6 pm on Thursday. The national safety level is 75 micrograms.

With rain forecast, the Beijing-Tianjin-Hebei region will also see the haze ease, with pollution expected to disperse by Tuesday, according to the ministry.