Short-video app TikTok has halted operations in Hong Kong, according to a notice posted on its website.
The company flagged the move earlier this week after China imposed a new security law on the city.
The law has restricted freedoms in the semi-autonomous territory, raising concerns of official oversight of social media.
Other social media companies such as Facebook and Twitter are also reviewing operations in Hong Kong.
TikTok has come under scrutiny from the US and other countries because of concerns it could share user data with Chinese authorities.
The app was launched outside of mainland China by Beijing-based ByteDance to reach a global audience.
Separately, a spokesman for the app, said on Friday that TikTok might come under a new business structure.
"As we consider the best path forward, ByteDance is evaluating changes to the corporate structure of its TikTok business," the spokesman said in an emailed statement.
He also reiterated previous pledges that ByteDance would refuse to share TikTok user data with Chinese authorities.
"We have never provided user data to the Chinese government, nor would we do so if asked.
" TikTok has increased its popularity during global coronavirus lockdowns with about 315 million people downloading the app in the first three months of this year, according to research firm Sensor Tower.
US Secretary of State Mike Pompeo and an Australian member of parliament have recently suggested the app needs more scrutiny over its data and privacy policies because its headquarters are in China.
Mr Pompeo has banned state department employees from downloading the app and suggested the app could also be banned in the US.
However, the company denied that it represented a security risk.
"TikTok is led by an American CEO (former Disney executive Kevin Mayer based in Los Angeles), with hundreds of employees and key leaders across safety, security, product, and public policy here in the US.
We have no higher priority than promoting a safe and secure app experience for our users," a spokesman said.