China's Sina Weibo microblog nears identity deadline
Efforts to censor messages posted to Weibo have not prevented false rumors from spreading
China's most popular microblogging site has said it expects 60% of its account holders to have registered accurate details about themselves by a state-imposed deadline.
Sina Corp's Weibo service - which is often compared to Twitter - has an estimated 260 million users.
Beijing's local government demanded that operators based in the city must obtain the information by 16 March.
The move was ordered to prevent the "spread of harmful" false rumours.
Users have been told to provide their name and mobile telephone number which must then be verified. Those who refuse will be barred from posting messages and will be limited to reading others' entries.
Examples of recent false stories include reports that North Korea's leader, Kim Jong-un, had been assassinated during a stay at the country's embassy in Beijing, and a claim that people had taken syringes containing HIV-infected blood to Beijing to use in attacks.
Sina's update coincides with a study highlighting how Chinese censors already delete controversial messages from the service.
Researchers at Carnegie Mellon University in Pittsburgh suggested that entries discussing political protests, the banned Falun Gong movement and pornography were among topics targeted by both automatic checks and human censors.
A separate study by BBC Monitoring suggested that the Chinese authorities wanted to use Weibo to "maintain social stability" rather than undermine the platform.
It noted that 141 deputies to the National People's Congress (NPC) and 183 members of the Chinese People's Political Consultative Conference (CPPCC) had signed up to the service - a move which attracted a lot of attention in the local media.
Although that still accounts for less than 10% of the deputies involved in the country's parliament and top political advisory body, the action appears to have proved popular.
A poll quoted by the semi-official China News Service (CNS) suggested that over 70% of the Chinese public thought that online expressions "will become a new avenue for China's democratic development", and nearly 60% thought that "it can help draw the government closer to the people".
CNS also reported how Cai Qi, a deputy from Zhejiang with more than one million followers, had asked for suggestions about what he should discuss in parliament. The article said he later based his proposals on some of the 12,000 replies he received.
Popular China Central Television (CCTV) host and CPPCC member Cui Yonguan said last month: "If several thousand people communicate with ordinary people and netizens every day, they may no longer have so much discontent in their hearts."
However, the Guangzhhou-based Southern Metropolis Daily newspaper published a commentary earlier this month saying that Weibo's rise could not substitute genuine "systemic reform".
It said the service provided "good democratic training" to the public, but added that there was a risk of social upheaval so long as deeper reforms remained indefinitely delayed.