At least a dozen popular public WeChat accounts - some followed by hundreds of thousands subscribers - were shut down or suspended yesterday.
Some of the accounts were operated by popular columnists, such as Xu Danei and Luo Changping, or by online news outlets, such as NetEase. Xu's account alone had an estimated 200,000 subscribers.
WeChat's public instant-messaging accounts have became a popular venue for discussing political issues in recent months as more established online social networks, like Sina Weibo, lost subscribers. The China Internet Information Centre said 37 per cent of users who quit weibo last year started using WeChat, which is run by internet giant Tencent.
Industry insiders said the suspension order was handed down without giving a reason yesterday afternoon. Most of the accounts that were shut down were known for posting commentaries and articles on current affairs.
"No reason was given," and insider said. "Some of the accounts were shut permanently."
People who clicked on affected accounts were greeted with a pop-up message saying the account had been shut for violating regulations. It was unclear how long the block would last.
The suspended accounts include one called Daxianggonghui (The Union of Elephants) and the Zhenhua (Speaking Truth) Channel, a commentary account run by NetEase.
The shutdown came on the last day of the politically sensitive National People's Congress session, in which Premier Li Keqiang held his high-profile annual news conference.
It also came amid wide speculation that the Communist Party would announce the fate of retired security tsar Zhou Yongkang, who is believed to be detained on suspicion of graft.
An internet operator who did not want to be named said the momentum to tighten control of new media platforms - especially WeChat - has been building since Lu Wei, a former Xinhua executive and Beijing vice-mayor, assumed the post of director of the State Internet Information Office last year.
Online news outlet Caixin reported last month that Lu doubled as general office director of the party's new leading group on internet security, chaired by President Xi Jinping.