Chinese archaeologists excavate an ancient tomb in Zhoukou city, Central China's Henan province, March 14, 2015. [Photo/Chinanews.com]

Chinese archaeologists discovered a series of tombs, some filled with ancient treasures, in a construction site in Zhoukou city, Central China's Henan province.

The archeological site in Xiangcheng, a county-level city, consists of 21 tombs built thousands of years ago, spanning from Warring States Period (475-221 BC) and East Han Dynasty (25-220), said Han Yanzhen, a scholar with cultural heritage institute of Zhoukou city.

Among them, 19 tombs are earth pit in shape and another two are brick-chambered tombs. Archeologists say all but five tombs were damaged by robbers.

Lots of funeral paraphernalia including pottery, bronze wares and jewelry were found in the tombs. A well-preserved bronze sword was one of the rarer discoveries, said Han, who added that it was well preserved due to the local soil condition.

Archaeologists say the treasures in the tombs can help researchers to better study the shape and structure of tombs, culture and customs between Warring States Period and East Han Dynasty.