Beijing police and public transport authorities have published a guideline to prevent the sexual harassment of passengers on buses and subways, but experts doubt it will solve the problem at its root.

The guideline, published by the traffic department under the Beijing Public Security Bureau on Monday, says women should not wear minimal clothing, such as mini skirts or hot pants when taking public transportation and should call police promptly if they are sexually harassed.

Women are advised to not sit on higher levels of buses and to stand on lower stairs, to avoid being the target of inappropriate picture-taking, and they should shelter their bodies with bags, magazines and newspapers.

In the case of sexual harassment, women can move to areas with more passengers to ask for help, or they can push men as buses and subways brake, the guideline added.

Xing Wei, a police officer with the department, said on Tuesday that the guideline has been published on the bureau's micro blog, asking that women be informed to increase awareness for protection.

"It is hard for us to collect evidence in sexual harassment cases despite cameras on buses and subways," Xing said. "It is also difficult to train public transportation workers to assist women in harassment prevention and response".

Now, police will warn, fine and detain perpetrators of sexual harassment in accordance with a security control regulation in place, he said, adding the heaviest punishment is a 15-day detention.

Wang Jiansheng, director of the security department with Fourth Transport Company under Beijing Public Transport Holdings Ltd, echoed the police officer, saying the best safety method is to ask conductors to remind women to protect themselves, rather than publish notices or establish a rule.

"When a woman informs the company that she has been sexually harassed, we'll report to the police and assist them in the investigation," Wang said.

Currently, the company has no channel or emergency system in place to take complaints from passengers and the majority of buses do not have cameras, he noted.

"After all, as a transport company, our main job is to take passengers to their destinations," Wang added.

However, Jiang Yue, a law professor at Xiamen University and an expert in women's rights, refuted the company's opinion and said the advisory from police will not solve the problem at its root.

"In fact, it's easy and necessary to require transport operators to provide warnings on buses and subways," Jiang said. "Passengers pay to take transport, so they have the responsibly to give them a safe environment".

Jiang suggested a law to prevent sexual harassment, adding harassment affects men as well as women.

Lin Lixia, an expert in women's protection with Beijing Zhongze Women's Legal Counseling and Service Center, agreed with Jiang, adding that a law should make the responsibility and punishment of the transport operators clear.

"Subway companies should establish a complaint channel for passengers and inform the public of what they can do in case of an emergency, including sexual harassment," Lin said.

Urging public transport companies to take such measures is the most effective prevention for now, because writing law can be a difficult process that takes time, she said.