The public has been urged not to take the law into its own hands after a video widely circulated online showed Chinese men beating a British tourist they suspected of indecently assaulting a woman.

Police confirmed on Thursday that a British man had been detained in connection with a reported attack on a woman in Beijing's Xicheng district at 11:20 pm on Tuesday night.

The man, whose identity has not been released, has a tourist visa and was drunk at the time of his arrest at Xuanwumen, according to a statement posted on the Beijing police Sina Weibo micro blog.

He was taken to Xuanwu Hospital for treatment on Tuesday night and transferred to a detention facility on Wednesday.

"The investigation is ongoing and further information will be released later," Zhao Feng, a police officer involved with the case, told China Daily.

A spokesman for the British embassy in Beijing said the embassy was aware of the incident but had received no request for consular support as of 7:30 pm on Thursday.

Edited footage of the alleged assault, which was recorded by a passer-by on a cell phone, was posted online and sparked outrage among Web users.

After showing a foreign man standing over a crying Chinese woman and being confronted by a Chinese man, the three-minute video skips to a brawl between the foreigner and Chinese men and then jumps a second time to the foreign man lying unconscious in the road.

Many Web users responded to the footage by praising the people who intervened in what police suspect was an indecent assault. However, legal experts said they were also concerned by the violence that followed.

"It was inappropriate and inhumane to attack the (British) man" after intervening in the situation with the woman, said Yi Shenghua of Yingke Law Firm.

"The (Chinese men's) behavior could be considered intentionally inflicting injury (under Chinese law), which carries a sentence of more than 10 years in prison. Stamping on a man's chest could kill him," he said.

"People should pay attention to how they vent their anger."

Guo Jianmei, a law professor at Peking University, agreed and added: "Although the (Chinese men's) actions were understandable, the public should rely on legal process to solve problems. The beating is really inhumane."

Following the incident, women are being urged to be vigilant when traveling at night and ideally to travel in groups.

"Find yourself a partner if you have to go out at night," said Jiang Yue, a law professor at Xiamen University and an expert in women's rights, who also suggested women learn some self-defense skills to protect themselves.

"There is no absolute safety, even in a crowded metropolis like Beijing," she said.