Three of the companies -- a cement factory, a steel company and a foundry -- are in east China's Anhui province. The other company is a dairy company in Cangzhou City, north China's Hebei province, according to the State Environmental Protection Administration (SEPA).

These companies have not carried out environmental impact studies, nor are they equipped with proper pollution control facilities, the administration said.

China's environment law stipulates that companies must design, build and use pollution control facilities in new production projects.

The administration urged local governments to fine these companies, halt their production and collect fees for pollutants already discharged.

It also pledged heavy punishment for five industrial parks in the provinces of Henan, Hebei, Gansu, Shandong and Shanxi, which have defied environmental rules by allowing heavily polluting companies into their parks.

A recent investigation by SEPA showed 87 percent of 126 industrial parks in 11 provinces had violated environmental laws and regulations.

It also showed half of the 75 waste-water processing factories in these provinces failed to properly process water or were not operating at all, and 44 percent of the 529 companies that SEPA inspected broke environmental rules.

On July 12, the administration unveiled a set of tough new rules to tackle worsening lake and river pollution.

The Ministry of Supervision has also ordered administrative punishments of local officials who neglect their supervision duties.

By June 30, more than 220,000 firms in China had undergone environmental checks, with more than 8,000 companies and 170 people punished for over-discharge of pollutants and other illegal practices