HOHHOT ?-- Archaeologists have excavated about 3,500 kilograms of ancient coins in north China's Inner Mongolia autonomous region, sources said Sunday.

The coins were found in three millennia-old coin pits in the ancient town of Huoluochaideng in Ordos City after police cracked three theft cases, said Lian Jilin, a researcher with the regional Institute of Cultural Relics and Archaeology.

Most of the coins were "Huoquan," coins commonly used in the Han Dynasty (202 BC - 220 AD), said Lian.

Archaeologists have also excavated over 100 casting molds from the relics of a coin workshop. The molds are believed to date back to the rule of Emperor Wudi (156 BC - 87 BC) of the Western Han Dynasty and the short-lived Xin Dynasty (45 BC - 23 AD) founded by Wang Mang.

Based on its size and cultural relics uncovered there, Huoluochaideng is believed to have been a major town in northern China during the Han Dynasty, said Lian.

The through-train method of the coin casting and storage seen in the relics of the ancient town is rarely seen in China and significant in the study of the ancient monetary system and casting technology, he added.