MOORESBORO, N.C. -- Eight protesters have been arrested after chaining themselves to construction equipment at Duke Energy's coal-fired power plant in western North Carolina.

The Charlotte Observer reported Wednesday the protesters are part of an environmental network called Rising Tide. The group blames such power plants' carbon dioxide emissions for global warming.

Rutherford County Sheriff Jack Conner said some protesters were stunned with Tasers. All were charged with trespassing, and four were charged with resisting arrest.

Duke Energy is building an 800-megawatt generator at its Cliffside Steam Station, about 50 miles west of Charlotte. Several environmental groups have asked a judge to halt the $2.4 billion project, saying the air quality permit allowing construction violates federal law.