An elderly man in central China's Henan province was irritated when the bus he usually takes pulled over sporting a sign saying "women only".

Since late April, the bus company in Zhengzhou has operated summer buses reserved for female passengers during rush hours. The buses are part of an effort to reduce sexual harassment during the summer, when women often wear skimpier clothing, and to make breast-feeding mothers more comfortable, according to Kong Chaoping, a representative of the company.

But Liu Tianhao, a male passenger, worried that "segregation" of passengers based on gender could lead to even greater negative impacts and a waste of social resources.

"It's discrimination against men to presume all of us are sexual harassers," a micro-blogger said on his Weibo account.

Public spaces designated for women have become increasingly visible in Chinese cities.

In Shanghai, four unusually large parking spots painted pink appeared at an office building, and an intercom system for emergency calls was installed.

Despite a warm welcome from some women's groups, others expressed dissatisfaction on social media.

Li Yinhe, a well-known Chinese sociologist and sexologist, said the suggestion was that "women cannot drive as well as men", even though the facilities were added under the guise of caring.

"Though not as serious as discrimination, women's parking does help to strengthen the stereotype of women as bad drivers," Li said. "As a matter of fact, there are plenty of women with excellent driving skills."

Some believe designating public spaces for women demonstrates courtesy and consideration.

The idea of "ladies first" should be valued in a civilized society, as women are still a vulnerable group in some ways, wrote commentator Yang Lan on news portal rednet.cn. Still, giving women priority in certain circumstances is justified, Yang added.