China has ordered producers of films and TV shows to limit the amount of smoking depicted on-screen. (Associated Press)

China is ordering makers of films and TV shows to limit the amount of smoking depicted on-screen, the latest effort to curb rampant tobacco use in the country with the largest number of smokers in the world.

The order from the country's State Administration of Radio, Film and Television — viewed Tuesday on its website —orders producers to minimize plot lines and scenes involving tobacco and show smoking only when necessary for artistic purposes or character development.

Minors under age 18 cannot be shown smoking or buying cigarettes, and characters may not smoke in public buildings or other places where smoking is banned.

Where possible, actors and directors are encouraged to leave smoking out of their productions, the circular said, adding that images of smoking in movies and television shows were out of sync with government efforts to control tobacco use.

The order does not mention entertainment imported from other nations. Hollywood blockbusters have had success in the Chinese market despite revenue quotas that effectively limit how many foreign productions are released.

China has been tightening up restrictions on smoking over the past decade, banning tobacco advertising and sponsorships of major sporting events

That's part of a slow realization of the massive toll heavy tobacco use is taking on an aging, increasingly urbanized population. Tobacco use is linked to the deaths of at least 1 million people every year in China, where 300 million people (or nearly 30 percent of adults) smoke.

While numbers of smokers have remained flat for the past decade, mortality rates among them are rising fast. If trends continue, by 2030 an estimated 3.5 million Chinese will die from smoking each year, according to a report issued last month by a group of prominent Chinese public health experts and economists.

The report cited China's failure to take basic measures such as passing a national law to ban smoking in indoor public places and raising the price of cigarettes.