KUNMING, May 30 (Xinhua) -- Chinese archaeologists have discovered a graveyard housing a large group of ancient tombs in southwestern China's Yunnan Province, in which more than 300 funerary objects have been unearthed.

Excavation of the tombs in Qiaojia County, Zhaotong City began in March. The graveyard, covering approximately 6,000 square meters, is located beneath a huge hydropower station in the Jinsha River basin. An estimated area of 5,000 square meters has been excavated so far.

More than 300 items, including pottery, stoneware and ancient shell coins were discovered in about 550 tombs.

The tombs are believed to date back to the early Bronze Age, some 2,000 years ago, according to Kang Lihong, associate researcher with the Yunnan institute of cultural relics and archaeology.

"The climate of the Jinsha River basin is hot and dry, so the corrosion rate has been slow and the potteries and shell coins as well as the skeletons in the grave are quite intact," Kang said. "The graveyard might belonged to a certain tribe or an ethnic group."

The excavation work is estimated to be completed in early June.