Three people were injured, one seriously, when part of the ancient city wall in Northern China's Gansu province collapsed on Monday morning, the Lanzhou Evening Post reported on Tuesday.

The section of wall that fell down around 7:30 am was in the western part of the old town in Huanxian county, Qingyang city, and measured about 20 meters wide and 7 meters tall.

Three people were buried in the collapse. Houses and cave dwellings of families living under or around the wall were also damaged.

Rescue work began soon after the collapse, and the three injured people were rescued and sent to hospital for treatment. Another 60 people living around the collapsed wall were also evacuated.

According to a worker from the county's museum, many parts of the city walls were built from the Qin Dynasty (221-206 BC) to the Ming Dynasty (AD 1368-1644) in the county. The collapsed wall was part of the county's heritage from the Ming Dynasty, the worker said.

Local authorities have begun to take measures to prevent a collapse from happening again.