The ancient Chinese city of Xi'an may be 2,500 years older than originally estimated, according to new archaeological findings at a nearby relic site.

A major ancient graveyard belonging to the Miaodigou period has been discovered northeast of the Yangguanzhai ruins, which belonged to a late Neolithic group known as the Yangshao. The new site has an area of 90,000 square metres and an estimated 2,000 tombs, China News Service reports.

The scale of the civilian graveyard is unprecedented and the human remains are densely distributed, said Yang Liping, the chief archaeologist, noting that only 300 of them have so far been cleaned and checked.