China's efforts to clean up the Internet have resulted in 15,000 arrests related to cybercrimes, authorities revealed on Tuesday.

The country's Ministry of Public Security has been cracking down on illegal Internet activities, and plans to increase enforcement even more, it said in an online post.

The ministry has so far investigated 7,400 Internet crimes, resulting in the large number of arrests. It's unclear during what period the investigations took place, but the ministry cited a case that went as far back as last December.

The alleged crimes include hacking attacks, cyber fraud, and the promotion of gambling.

In one such case, the arrested suspects took control of a company's website and filled its pages with online gambling content. Seven people were eventually arrested, and found to have allegedly hacked into 2,000 company websites.

In another instance, the suspects sent SMS messages to mobile phone users that contained a link to download malware. The malware could then control the user's phone, and steal personal information, including bank card numbers, loaded inside.

China has the world's largest Internet population at 668 million Internet users. But as the Internet grows, so has the potential for cybercrime. SMS messages containing links to malware have been particularly on the rise, according to the country's National Computer Network Emergency Response Technical Team. One such piece of malware, called "xxShenqi" managed to infect 110,000 users across the country last year.

Besides cracking down on Internet crimes, China is also deleting what it finds to be offensive and harmful content found on the Web. This includes gun-related violence, pornography and gambling, resulting in the Ministry of Public Security investigating 66,000 websites and Internet posts, it said Tuesday.

China is well-known for its online censorship, and the country has made it a priority to step up regulation of the Internet's content, especially on social media platforms.