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.

He told the Beijing Morning Post that he had come to the Chinese capital "only to see the pandas".

"The seven-hour train ride was exhausting, and I drank bottles of beer when I arrived then had a nap," he added.