The city's first law to ban smoking, which applies to 12 types of public venues, such as schools, hospitals, shopping malls, Internet caf and elevators, took effect Monday. Random checks showed that most establishments are following the law, and volunteers are working to enforce it.

The law requires public venues, including bars, restaurants and hotels, to set up designated non-smoking areas. People who smoke in banned areas will be first warned by supervisors, and then fined 50 yuan (US$7.30) to 200 yuan if they refuse to stop, according to the law.

On the first day the new law took effect, a China Daily reporter randomly selected eight restaurants and found that most restaurants have set up non-smoking areas with "No smoking" signs. Some also posted the supervision hotline numbers on the wall.

However, a common phenomenon is that most non-smoking areas in the restaurants are smaller than the smoking areas and there is no partition between them.

Tang Liang, manager of a Cantonese restaurant on Huaihai Road, said: "Our restaurant had a non-smoking section before but we have doubled its size according to the new law."

Even so, the space of the non-smoking section only accounts for 30 to 40 percent of the entire restaurant.

The smoking ban seemed to be well received in local schools and hospitals.

In some shopping malls and supermarkets, people who held a burning cigarette soon put them out at the volunteers' persuasion.

Shi Qiao, a 33-year-old manager of a caf, welcomed the new law.

"What the authorities are doing will not only stop people from smoking but also save people's lives," he said. His caf receives more than 300 customers each day, and more than half of them smoke, he said.

"The new law is good news for all of the people who work and breathe in second-hand smoke every day," Shi said.

According to earlier reports, more than 80 percent of local residents support the new law.

Alex Zhang, a 28 year-old IT engineer and an occasional smoker, said: "Maybe it is a good way to help smokers like me quit the habit. Also, it helps the victims of passive smoking."

Statistics from health authorities show the city's overall smoking prevalence is 25.22 percent, with male smoking rate 49.92 percent.

About 90 percent of residents suffer from passive smoking, while 47.6 percent of students suffered passive smoking at home.

Shi Qiao also noted that many restaurant owners would not report offenders due to a fear of losing business.

"If your guests refuse to put out the cigarette or enter the smoking areas, you can do nothing. After all they are the source of your business," he said.

The local health authority has registered 20,000 local volunteers citywide to enforce the law.