China's media regulator vowed a crackdown on online crimes and strengthened monitoring to prevent overseas hostile forces from infiltrating through the Internet, state media said on Monday.

Wang Chen, head of the Information Office of the State Council, said on Friday the country would intensify a crackdown on online crimes as part of an ongoing campaign that he said netted more than 5,510 suspects last year.

Xinhua news agency reported his comments as part of a story on an online drug ring on Monday.

Wang said China would also strengthen monitoring on harmful information on the Internet in a bid to block overseas harmful information from spreading in the country and prevent overseas hostile forces from infiltrating through the Internet, Xinhua said.

As China's Internet population has grown by leaps and bounds, so too have government efforts to screen out any information that might threaten Communist Party rule.

China now has 404 million Internet users, including 346 million who use broadband and 233 million who use mobile phones, Xinhua said, citing Wang.

China last year began a three-phase campaign to tighten Internet controls and reduce citizens' ability to operate anonymously on the Internet. It bills the campaign to its populace as a drive against pornography.

It has blocked a number of foreign social media sites since last year, including Facebook, YouTube and Twitter.

Regulators keep a particularly strict eye on websites geared toward ethnic minorities, particularly Tibetans, Uighurs and Mongolians, who have active exile communities and domestic populations who chafe at rule by Beijing and policies that benefit the Han majority.

Online fraud and rampant viruses and hacking are also a problem in China, where users new to the Internet tend to be more trusting of unknown sites and information requests. (Reporting by Lucy Hornby; Editing by Nick Macfie)