BEIJING - Chinese cigarette firms have been accused of dodging a ban on conventional advertising by finding new ways to market their products online.

These companies have established online smoking communities, posted tobacco-themed micro films, and even developed Internet games that incorporate cigarette branding.

On the website of "Yanyue," which literally means "smoke pleasant," netizens are being invited to take part in a jigsaw puzzle contest. Players will find the picture they complete is the logo of a cigarette brand. All prizes are packs of cigarettes.

The Longyan Tobacco Industrial Co Ltd. has implanted one of its brands into an online soccer game, and invested in the shooting of a micro film called "the time travels of a cigarette."

"All these online acts are essentially tobacco advertisements," said Li Qiang, a researcher with the Tobacco Control Office of the Chinese Center for Disease Control and Prevention (China CDC).

China signed the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) in 2003. The convention stipulates that signed parties should comprehensively ban all tobacco advertising, promotion and sponsorship.

Under the country's Advertising Law enacted in 1994, tobacco ads are not allowed in broadcasts, movies, television shows, newspapers or periodicals, and should not be placed in waiting rooms, cinemas, meeting halls or stadiums.

However, online tobacco advertising has become a legal loophole, said Li.

He said a tobacco control policy evaluation launched by China CDC found 68 percent of smokers and 84 percent of non-smokers "disagree" or "strongly disagree" with the notion that tobacco companies should be allowed to advertise at will.

Wang Ke'an, director of a non-government organization on tobacco control called ThinkTank, urged revision of the law to better match the current situation and meet the conditions of the FCTC.

More severe penalties for breaches of tobacco advertising laws should also be introduced, said Wang.

Statistics from China's health authorities show China has 300 million smokers, and 28.1 percent of people over the age of 15 smoke. The smoking rate among males has reached 52.96 percent.

Yu Xiuyan, a public health researcher at the China University of Political Science and Law, said the online tobacco marketing has obviously violated the FCTC, and should be banned.

According to Yu, the tobacco industry's advertising through social media and other online activities particularly targets the young, especially teenagers.

"Teenagers, most of whom are netizens, are very likely to be influenced by these ads and start smoking," she said.

Angela Pratt, a technical officer with the Tobacco Free Initiative of the WHO Representative Office in China, said online advertising has become an important means adopted by tobacco companies because its low cost, ease and the potential size of the audience.

A WHO study found that one-third of young smokers started smoking because of access to tobacco advertising, promotion or sponsorship, according to Pratt.

She said banning tobacco advertising in all its forms is the most cost-effective tobacco control measure.

As of 2012, 86 countries have comprehensively banned tobacco advertising, promotion and sponsorship, since the campaign was initiated by Norway in 1975.

May 31 marks the 26th World No Tobacco Day, an occasion promoted by the WHO and its partners. This year's focus will be on banning tobacco advertising, promotion and sponsorship.