A Chinese group has asked Japan to return a 1,300-year-old stone stele looted by Japanese soldiers early last century from northeastern China.

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In a letter addressed to Japanese Emperor Akihito and the Japanese government on Sunday via the Japanese Embassy in China, the China Federation of Demanding Compensation from Japan (CFDC) said the Honglujing Stele, which documents China's endorsement of the first king of the Bohai Kingdom (698-926) in 713 A.D., should be handed back to China as soon as possible.

CFDC president Tong Zeng told Xinhua on Monday that so far the federation has not yet received any reply from Japanese authorities.

This is the first time a Chinese civic group has asked the Japanese imperial family for the return of a looted Chinese relic.

About three meters wide, 1.8 meters tall and two meters thick, the Honglujing Stele shows that the first king of the Bohai Kingdom was conferred the title by an emperor of China's Tang Dynasty (618-907).

The stele was originally placed in Lushun in northeast China's Liaoning Province, but now sits in virtual seclusion in the Japanese imperial palace after the Japanese army shipped the stele to Japan in 1908 as a wartime "trophy." Lushun was controlled by Russia before the war.

Established in 2006, the CFDC seeks compensation for personal, material and spiritual damage caused by Japanese militarism during the country's aggression against China in the 20th century.

According to Wang Jinsi, a CFDC director in charge of recovering cultural relics, the Honglujing Stele is one of the most important relics taken from China to Japan in last century.