The United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Committee approved here Thursday an extension of China's Imperial Tombs of the Ming and Qing Dynasties on the World Heritage List.

Sources with the ongoing 28th Session of the World Heritage Committee said the extension, which included three tombs in China's northeast Liaoning Province, would add an additional 338.34 hectares of protected area to the tombs already inscribed on the list.

The Imperial Tombs of the Ming and Qing Dynasties were first inscribed on the World Heritage List at the 24th session of the Committee in 2000. In 2003, an additional group of tombs in Beijing and east China's Jiangsu Province were included in the inscribed site.