YINCHUAN, Aug. 24 (Xinhua) -- Eight people in northwest China's Ningxia Hui Autonomous Region have been given prison terms for selling coins which they stole from an archeological site, a local court said on Wednesday.

They were sentenced to up to ten years by Huinong District People's Court in Shizuishan city of Ningxia.

The court heard that, in August 2014, Wu drove Zhou and Li to the site of the ancient Shengwei city, where, with the aid of the guard Lu, they filled several sacks with coins. On May 21 and 22 last year, they returned to the scene to steal more.

Wu later sold the coins for around 220 yuan (about 33 U.S. dollars) per kilogram.

Police have retrieved most of the 400 plus kilograms of coins stolen last year, but failed to get back those taken in 2014.

An official with the cultural heritage bureau of Ningxia told Xinhua that about over 100,000 coins, mostly from the Song Dynasty (960 - 1279), and weighing close to 500 kilograms, were involved.

Zhou and Li were sentenced to ten years each. Lu was also jailed for ten years and fined 8,000 yuan. Other members of the group received lesser terms.

The site was first excavated in the 1960s. Apart from coins, pottery, bottles and bowls, many weapons were also found there, important in the study of Western Xia (1038 -- 1227) culture.