China tightens internet use rules for blogs and internet chat rooms
Users of blogs and internet chat rooms will be required to register their names with operators and promise in writing to avoid challenging the communist political system.
The announcement follows what technology companies say are official efforts in recent weeks to block virtual private networks that are used to circumvent China's extensive Internet filters.
China has the world's biggest population of internet users with 649 million people online but increasing censorship has limited the popularity of social media.
Beijing has required Internet companies since 2012 to obtain real names of some users. But compliance was uneven and the rules failed to specify what services were covered.
The latest announcement extends that "real name" registration requirement to blogs, microblog services such as the popular Sina Weibo and website comment sections. Such settings offer many Chinese their only opportunity to express themselves in public in a society in which all media are controlled by the ruling Communist Party.
The rules also require internet services for the first time to have users sign a contract that includes a pledge to refrain from "illegal and unhealthy" activity.
Wednesday's announcement affirmed an earlier prohibition against posting material deemed a threat to state power or national security - terms the ruling party uses to describe opposition to communist rule. It said operators will be required to deactivate accounts of violators.
The ruling party encourages Internet use for business and education but tries to block material deemed subversive or obscene. Beijing regularly launches new censorship initiatives to respond to changes such as the growing popularity of social media.
The Cyberspace Administration of China said the latest rules are needed to combat "username chaos". In a statement, the agency said users took inappropriate online names such as Putin and Obama, promoted "vulgar culture", committed fraud by pretending to be Communist Party officials or agitated for separatist causes.
Operators will be required to assign an employee to review and keep track of user details to ensure they comply, the agency said.