Anti-smoking campaigners have called on the authorities to do more to stop actors from lighting up on the nation's screens.

According to a Chinese Association on Tobacco Control study this year of 70 popular movies and TV dramas, only nine TV shows and 11 movies did not show smoking.

Suo Chao, the association's spokesman, said the "frequent examples of smoking in films and TV dramas are not in accordance with China's stance on tobacco control".

Of China's 30 top-rated TV dramas last year, 21 depicted smoking, with an average of two scenes with smoking per episode, according to the association's research.

Smoking was shown in 29 of the nation's most popular movies last year, with an average of 14 scenes with smoking per film.

Xu Guihua, the association's deputy director, said that although the study revealed a high incidence of smoking scenes, the number of such scenes has declined over the past five years, and the number of tobacco-free movies went from four in 2007 to 11 last year.

Of the top-rated TV dramas, nine had no smoking in 2012, up from two in 2007.

Xu warned that studies indicate teenagers are "16 times more likely to try smoking" when they see their idols lighting up on the large or small screen.

Yang Gonghuan, a tobacco control expert at the Chinese Center for Disease Control and Prevention, said authorities should do more to enforce no-smoking regulations and curb smoking scenes in films and TV.

"China's regulations against smoking are more a formality and have scant deterrent power," she said.

Little had been done to enforce the regulation issued by the State Administration of Radio, Film and Television in 2011 requiring movies and TV dramas to reduce smoking scenes, she said.

The administration demanded a reduction in smoking scenes in films and TV dramas in 2011 after complaints arose that China has failed to keep its commitment to the World Health Organization.

Smoking scenes with juveniles present and tobacco brands should not be allowed to appear in films or TV dramas, said the announcement posted on the administration's website.

And scenes that show smoking should be as short as possible, it said.

Suo, from the Chinese Association on Tobacco Control, said a similar situation is common in universities and colleges, where a smoking ban has been poorly implemented due to insufficient supervision and a lack of penalties for offenders.