BEIJING - China's environmental watchdog has punished eight power plants for violations of the law on control of sulfur dioxide emissions, a main indicator for measuring air pollution.

The eight power plants -- two of which are in Henan, and the others in Inner Mongolia, Jiangsu, Hunan, Guangdong, Sichuan and Gansu -- include some affiliated to Chinese power giants China Power Investment Corporation, China Guodian Corporation, China Huadian Corporation and China Datang Corporation, said a statement jointly issued by the Ministry of Environmental Protection and the National Development and Reform Commission.

The plants were punished for excessive discharges of sulfur dioxide, deactivating desulfurizing or emission-monitoring equipment, as well as fabricating emissions data, said the statement published on the ministry's website.

The ministry has ordered the plants to correct their practices before the end of this year and pay fines for the violations. The fines in these cases were unspecified, but plants may be ordered to pay up to 50,000 yuan for fabricating emissions data, according to law, and between 10,000 and 100,000 yuan for excessive discharges of sulfur dioxide.

The statement also told relevant authorities to deduct the subsidies paid to the plants under the state's subsidy program for desulfurization efforts.

China has announced its aim to reduce the country's sulfur dioxide emissions by 8 percent during the nation's 12th Five-Year Plan period (2011-15).

According to a statement issued by the ministry last month, sulfur dioxide emissions in China totaled 11.14 million tons between January and June this year, a drop of 1.74 percent year-on-year.