China said on Sunday that it had ordered smartphone app stores to stop offering Didi, the country's largest ride-hailing app, after finding that it had illegally collected users' personal data.
China's cyberspace regulator said it told Didi to make changes to comply with Chinese data protection rules, four days after Didi began trading on the New York Stock Exchange.
The Chinese regulator did not specify the nature of Didi's violation in a statement on its social media feed.
Didi responded by saying it had stopped registering new users and would remove its app from app stores. It said it would make changes to comply with rules and protect users' rights.
China has been clamping down on its home-grown technology giants over antitrust and data security concerns.
Didi made its trading debut in the U.S. on Wednesday in an IPO that valued the company at $67.5 billion, well down from the $100 billion it had hoped for.
On Friday, China announced an investigation into Didi to protect "national security and the public interest," prompting a more than 5% fall in the price of its shares.