China has ordered online platforms to punish staff who spread "illegal" content domestically, in the latest move by authorities to tighten policing of the web.

Service providers must "establish a sound information security management system", the Cyberspace Administration of China (CAC) said in a Monday statement.

"While we benefit from new applications or technologies... they are also improperly used by some people to post illegal information or even to commit crimes," it said.

It was unclear what companies would have to do to comply with the new standards.

In a separate regulation issued the same day, the CAC called for tighter oversight of website workers.

"Some content posted by the staff of news websites without sufficient training is still improper or illegal," it said.

Administrators should set up a blacklist to track people who violate rules, "while the websites they work for should also punish them", it added without going into details.

Both regulations take effect on December 1.

China tightly controls the internet through a censorship system known as the "Great Firewall" and closely monitors social media networks for sensitive content.

Regulations in force since 2000 decree that websites are responsible for "ensuring the legality of any information" posted on their platforms.

In July the CAC said it had held a meeting with representatives from domestic tech giants Baidu, Sohu, Tencent and Netease among others to inform them of multiple content violations on their platforms.

The offences included misinterpreting policy directives, disseminating false information, distorting Chinese Communist Party history, plagiarising photos and challenging public order.

Previous regulations that came into force on June 1 require online platforms to obtain a licence to post news reports or commentary about the government, the economy, the military, foreign affairs and social issues.

In other recent moves, authorities have closed dozens of celebrity gossip blogs and issued new rules concerning online video content to eliminate programmes deemed offensive.