China announced on Monday probes into two more US-listed Chinese companies, a day after banning ride-hailing giant Didi Chuxing from app stores in the wake of its huge US initial public offering.
The country's major internet firms wield massive influence among consumers, but have for almost a year had their wings clipped in a regulatory crackdown that scuppered IPOs and hit business as the government seeks to rein in their influence.
The latest moves hit newly listed companies Full Truck Alliance -- a merger between truck-hailing platforms Yunmanman and Huochebang -- as well as Kanzhun, which owns online recruitment platform Boss Zhipin.
All three platforms have been told to stop new user registration during the period of investigation -- which was to "to prevent security risks to national data, safeguard national security and protect public interest", according to the Cyberspace Administration of China.
Just hours earlier, the watchdog ordered the removal of Didi from app stores following a similar investigation, throwing a wrench in the company's growth plans after a bumper New York IPO last week raised more than $4.4 billion.
The Administration issued the order on Didi -- which has nearly 500 million users and 15 million drivers -- after investigations found its user data collection and use in "serious violation" of regulations.
It also cited national security for the action, in an unusual move against a domestic tech firm.
The move was lauded by state media with the Global Times saying in a commentary that Didi appeared to have the ability to conduct "big data analysis" on a person's behaviour and habits, constituting a potential information risk.
"We must not allow any internet giant to become a super database of Chinese personal information even more detailed than the state, let alone give them the right to use this data at will," it said.
Last year, Chinese authorities pulled the plug on a planned record-busting $34 billion IPO by Alibaba's financial arm Ant Group, before launching an anti-monopoly probe into the tech behemoth.