LANZHOU, April 10 (Xinhua) -- A joint burial tomb dating back to the Han Dynasty (202 B.C.- 220) has been found in northwest China's Gansu Province, local authorities said Tuesday.

The tomb was found at a construction site for an expressway in Zhuanglang County, Pingliang City. The county museum sent its staff to the site to investigate after receiving the report.

Cultural relics workers said that the tomb is believed to date back to the Han Dynasty based on the type and burial objects.

The tomb is a joint burial tomb consisting of a tomb passage and coffin chamber containing two coffins, one for a man and another for a woman, according to Li Xiaobin, deputy curator of the museum.

Iron nails, copper rings, beads and a coin were found in the tomb.

Li said the discovery could shed more light for the research into the tomb types, funeral customs, society and economy of the Han Dynasty.