Police in Guangzhou, Guangdong province, have detained 133 suspects after busting a criminal gang that they said stole the personal data of local residents.

Lu Feng, director of the general office of the Guangdong provincial Department of Public Security, said the special police operation earlier this month, involving 560 officers, raided 21 secret dens across the city starting in the early morning of June 12.

"Police also seized 35 mobile phones, 19 computers, 10 sales devices and other criminal tools, plus plenty of personal data during the operation," Lu told a news conference on Wednesday.

The gang seriously compromised people's privacy by selling the personal data, he said.

The Guangzhou operation is just one part of a special campaign launched to fight the theft of personal data in the province between June 12 and 17, according to Lu.

During the campaign, police across the province detained 379 people suspected of infringing personal data.

Meanwhile, police busted 78 criminal gangs that they said stole and resold the personal data in the province. Many identity cards, bank cards, mobile phones, computers and other criminal tools and stolen personal data were seized, Lu said.

Some of the criminal gangs organized telephone fraud and kidnapping, and illegally demanded payment of debts from some creditors, in addition to other crimes.

Lu hinted that more special operations will be launched in the coming months.

According to an annual report on the development of new media issued on Tuesday, stealing information and online telephone fraud account for 90 percent of the mainland's online crimes.

The stolen information was frequently used in other frauds, on gambling or pornography sites, or in other online crimes, according to the report.

The report was published by the Institute of Journalism and Communication Studies of the Chinese Academy of Social Sciences and Social Science Academic Press (China) on Tuesday.