China orders app stores to join register
China's internet regulator has ordered mobile app stores to register themselves with it immediately.
The Cyberspace Administration of China (CAC) said the move would help "promote the healthy and orderly development of the mobile internet".
Most smartphones in the country run Android, but Google does not operate its Play Store locally, meaning users go elsewhere to add software.
A report last year linked this to the spread of malware.
Cheetah Mobile Security - a Beijing-based firm - reported that more than 1.4 million Chinese users' mobile devices had been struck by infections as of January 2016, making it the worst afflicted nation. India and Indonesia were in second and third place.
"[A] reason these countries have become the worst-hit ones is that third party app markets are prevailing in these areas, and most of these third party app markets have been contaminated by malware due to weak monitoring," it said.
CAC said the register was also intended to tackle the publication of "illegal information".
This follows previous efforts to censor what appears online, including a recent demand that Apple remove the New York Times from the Chinese version of its iOS App Store.
The US newspaper was the first to report the watchdog's move outside of China itself.
Because of the Play store's absence, Android users in China typically go to stores operated by local tech giants including Tencent, Xiaomi, Baidu and Huawei.
However, the Japanese cybersecurity firm Trend Micro has noted that some Chinese citizens also go to less secure stores specifically to find apps that are unavailable elsewhere.
CAC's notice does not specify what steps it will take to ensure all marketplaces register themselves and supervise their contents to its liking.
But since there are other ways to make handsets "sideload" software, one expert suggested the effort could have unintended consequences.
"If you turn off some of the settings you can bypass the app stores and install software from elsewhere," commented Dr Steven Murdoch from University College London.
"And that creates a security problem."
Analysis: Dong Le, BBC Chinese Service
The move fits into a broader picture of the government stepping up control over the flow of information on the internet.
In announcing the news, the authorities have acknowledged that mobile apps - like internet websites - have become a major carrier of information, and present a challenge to China's internet police.
Many of the homegrown mobile apps are believed to contain security loopholes.
But Chinese authorities are clearly worried that they may offer a way to circumvent its Great Firewall to enable their users to access websites and information that are deemed subversive.