Gu Gu the panda is said to have suffered no harm after the event

Zhang Xinyan, 35, had drunk four draught beers before deciding to enter the Beijing Zoo pen belonging to six-year-old male panda Gu Gu.

The startled Gu Gu bit both legs of his intruder, who responded by biting "the panda on its back", Mr Zhang was quoted by state media as saying.

Mr Zhang said he had not realised pandas could be violent.