A section of Jin Dynasty (1115-1234) Great Wall in northeast China has been severely damaged by a road construction project, according to the local cultural authorities on Friday.

"The section of the Great Wall in Heilongjiang's border region with Inner Mongolia has been irrevocably damaged," said Zhao Pingchun, deputy head of the relic protection office under the Heilongjiang Provincial Culture Bureau.

Heavy construction traffic has damaged the supporting walls and ditches of the Great Wall according to a Xinhua reporter on location.

Wang Dafang, a relic protection official with the Inner Mongolia regional culture bureau, confirmed that "damages were made by a road construction project on the Inner Mongolia side of the Great Wall."

The officials said Friday the construction on both sides of the Great Wall has been stopped. Authorities from Inner Mongolia and Heilongjiang are investigating the damages.

"Workers have dug footing grooves 14 meters long and 10.5 meters wide for the building support beams for a viaduct, which are only 15 meters away from the main body of the Great Wall," said Zhao, who made a field investigation on the Great Wall damage in Gannan County, Heilongjiang.

Wu Jie, a curator in an archaeological museum in Arong Banner, Inner Mongolia, said that big holes were dug five meters away from the main body of the Great Wall.

The cultural authorities said workers were building an over head intersection of the Arong Banner-Boketu Highway on the Inner Mongolia side of the Great Wall and the Qiqihar-Gannan Highway on the Heilongjiang side.

The viaduct was to span the section of the Great Wall.

The 5,500-km Jin Dynasty Great Wall spans 4,600 km in China, and has parts of Mongolia and Russia.

The Chinese section of the Great Wall was added to the list of protected state key cultural relic sites in 2001.

However, when asked by a Xinhua reporter, a construction worker at the site said he knew nothing about the protection status.

Zhao said construction firms have evaded China's Relic Protection Law, which requires project managers to report the project plan to the relic protection authority for approval before carrying out the work.

The Jin Dynasty Great Wall was built by the Nuzhen nomadic to prevent invasion from Mongols. The Great Wall was also called the Boundary Ditch of the Jin, since it was formed by digging ditches, within which the walls were built.

Damaging the state key cultural relic site is punishable by fines or jail terms.

Five miners were sentenced to one-to-three years in Inner Mongolia last year for causing damages to a section of the Ming Dynasty (1368-1644) Great Wall while using heavy machinery for mining. So far, the case is the only Great Wall case that resulted in jail time for the offenders.