Police detained more than 5,400 criminal suspects in a 40-day crackdown. The campaign will remain a focus for police this year.

The police initiated the spring campaign in April and it continued to May 20.

Police said the crackdown involved a total of 7,600 criminal cases, an increase of 6.9 percent compared with the same period last year.

Wu Yijie, a police officer from the criminal case investigation corps said: "We will enforce strong measures to actively combat criminals, including those causing disturbances in a public place or group fights."

He said the police will also extend their efforts to combat illegal activities, such as blackmail and gangs controlling markets or businesses.

"These cases seem like common criminal cases, but we will intend to make in-depth investigations and analysis to determine the manipulators and organizers behind these activities," he said.

In the crackdown from April 9 to May 20, 25 gangs involved with such criminal activities were investigated, with 180 suspects detained.

Meanwhile, police continue to fight telephone fraud and professional, group, serial and property related crimes.

During the 40 days, property related cases in the city dropped by 8.9 percent, with 2,300 suspects detained.

The ongoing crackdown on prostitution will continue to the end of this year, police said, and they will make surprise inspections on KTVs, nightclubs and bath centers besides responding to reports from citizens.

He Angang, political commissioner from the public security corps, told METRO a special police force will especially target the five - star hotels, nightclubs, large-scale KTV s and private top-end business or hot spring clubs.

He said if an entertainment place is found to provide obscene shows, organize prostitution or provide venues for prostitution, it could have its license revoked or have its business suspended.

"These entertainment places are usually backed up by criminal gangs; carrying out the clean-up is conducive to fundamentally attacking these criminal gangs," he said.

Last week, 35 city entertainment places including the Heaven Earth nightclub, No 8 Club KTV, and Sunworld Dynasty Hotel KTV were closed for offences involving prostitution.

Around 1,100 were detained during the one-month crackdown, which started on April 11.