Beijing police have combated gambling and prostitution with "zero tolerance" in the past four years, smashing more than 17,000 gambling and prostitution gangs, and arresting more than 68,000 suspects, according to a statement by Beijing Public Security Bureau.

Of those arrested, 4,188 were criminally detained and 6,399 venues without business operating licenses have been closed.

In the past nine months, there have been 408 criminal detentions for prostitution, up 61.3 percent year-on-year, while 393 people were detained for gambling, a 9.8-perecent increase year-on-year.

The bureau said it pays attention to reports by residents and monitors the Internet for indications of illegal activities.

In August, police from six districts, including Chaoyang and Haidian, smashed 15 gangs suspected of running prostitution via instant messaging apps WeChat and QQ. Four people were criminally detained, the statement added.