US social media giant Facebook says it detected and removed accounts of a group of hackers in China who were using the platform to monitor Uighurs living abroad.
Facebook on Wednesday said the group targeted Uighur activists, journalists and dissidents living abroad in countries such as Turkey and the United States.
It said the hackers posed as students and journalists and created fake accounts on Facebook to build trust with the people they targeted.
The hackers did so in an attempt to trick their targets into clicking on malicious links in order to infect their electronic devices with malware to enable surveillance.
Facebook said it has notified nearly 500 people whose devices may have been compromised.
It said the hacking activity had "the hallmarks of a well-resourced and persistent operation while obfuscating who's behind it."
The US and European countries are criticizing Chinese authorities over alleged human rights abuses against Uighurs in the Xinjiang Uygur Autonomous Region. China denies the allegations.