China's environmental watchdog has halted production or further construction of five factories and three road projects that harmed the environment.

"All of them failed to provide proper environmental protection facilities when the projects were being built but went into operation anyway, which is against China's law and regulations," an official with the State Environmental Protection Administration (SEPA) said here on Thursday.

"If these projects do not upgrade their environmental prevention facilities within a fixed time limit, stricter punishment will be inflicted," the official added.

The eight projects were spotted by the SEPA in an initial checkup of pollution prevention facilities in 2,453 projects built during 2001 and 2005.

The official said the checkup will be made public when it is completed at the end of this year, implying that more polluting projects could be shut down.

The five factories that have been shut down produced coke, electricity and heat and chemicals in the provinces of Shanxi, Shandong, Sichuan and Hebei. Three road building projects in Shanghai, Zhejiang and Hebei were criticized for causing noise pollution, according to the SEPA.

Two coke ovens of Shanxi Luliang coking plant in central China's Shanxi Province were put into operation several years ago without waste water treatment equipment. The waste from the plant was being discharged into a tributary of the Yellow River.

The construction of the two coke ovens was completed before an environmental impact assessment had been completed, according to the SEPA.

Some regions have in recent years blindly launched energy-intensive, heavily polluting projects, the SEPA said in a statement.

The SEPA attributed the phenomenon to local governments' focus on economic development, in disregard of the environment, as well as a lack of supervision.