BEIJING - The number of drunk driving cases in China has dropped by 40 percent over the last year after the implementation of an amended law that imposes stricter punishments for the offense, according to a public security official.

Police across China have handled 368,000 drunk driving cases since May 1, 2011, when China's amended Criminal Law took effect, the Beijing News quoted Huang Ming, vice minister of public security, as saying on Wednesday.

The cities of Beijing and Shanghai both witnessed a sharp drop of 70 percent in the number of cases, according to Huang.

In 2011, drunk drivers caused 3,555 traffic accidents and killed 1,220 people, representing a year-on-year drop of 18.8 percent and 37.7 percent, respectively, official statistics show.

The amended law defines all drunk driving occurrences as criminal offenses, even if the act does not result in a traffic accident.

Under the current law, drunk drivers risk having their driver's licenses permanently revoked if they cause a serious accident, while the earlier version of the law imposed a license suspension of three to six months for drunk drivers.

According to the current law, drivers who have at least 80 milligrams of alcohol per 100 milliliters of blood in their body are considered drunk.