BEIJING -- Some 5,594 companies, or 66.2 percent of those examined, violated environmental standards during the latest round of air pollution inspections, China's environmental authority announced Tuesday.

The findings came after a month of inspections across 28 cities in the Beijing-Tianjin-Hebei region and other nearby areas, which resulted in the discovery of problems including excessive emissions and insufficient pollution control equipment.

Inspectors reported the issues to the local authorities for further investigation, the Ministry of Environmental Protection (MEP) said in a statement.

As of May 2, local authorities had shut down 131 companies and halted production at another 213 due to failure to meet environment protection standards.

Chinese enterprises were fined around 264 million yuan ($38 million) for violating standards in the first quarter of this year, the MEP said last month.

The ministry issued punishments in nearly 5,000 cases related to violations of environmental protection regulations and laws in Q1, up around 200 percent year on year.

In 224 cases, companies had to pay between 10,000 and 100,000 yuan per day after failing to rectify violations within the time frame set by the MEP.