SHANGHAI — Two prominent Chinese bloggers in exile said police were investigating their millions of followers on international social media platforms, in an escalation of Beijing’s attempts to clamp down on critical speech even outside of the country’s borders.

Former state broadcaster CCTV journalist Wang Zhi’an and artist-turned-dissident Li Ying, both Chinese citizens known for posting uncensored Chinese news, said in separate posts Sunday that police were interrogating people who followed them on social media, and urged followers to take precautions such as unfollowing their accounts, changing their usernames, avoiding Chinese-made phones and preparing to be questioned.

Li Ying, known as Teacher Li, came to prominence as a source of news about the White Paper protests, a rare moment of anti-government protests in mainland China in 2022. Teacher Li’s account on X, formerly known as Twitter, @whyyoutouzhele now posts news and videos submitted by users, which cover everything from local protests to viral videos of real-life incidents that are censored on the Chinese internet.

In a post Sunday evening, Teacher Li suggested people unfollow his account. “Currently, the public security bureau is checking my 1.6 million followers and people in the comments, one by one.”

Li shared screenshots of private messages he received from followers over the past few months, which claimed that police had interrogated individuals, and that one person had even lost their job.

As of Tuesday morning, Li had dropped down to 1.4 million followers on X.

International social media platforms like X and YouTube are blocked in China, but can still be accessed with software that circumvents the country’s censorship systems.

Wang, who has a million subscribers on X and 1.2 million followers on YouTube, also told his fans to unsubscribe.

In a written statement, the Chinese Foreign Ministry said it “didn’t understand the situation” and that it was not a diplomatic matter.

Li and Wang did not respond to requests for comment.

Over the past decade, Beijing has cracked down on dissent on Chinese social media, with thousands of censors employed both at private companies and with the Chinese state.

Chinese users expressing critical opinions online have reported being called, harassed or interrogated by police, with some called in for questioning and ordered to take down certain posts or delete their accounts. In some cases, users have been detained, with some spending up to two weeks in jail and a small number sentenced to years in prison.

More recently, Beijing has extended its reach to tracking non-Chinese platforms such as Facebook, Telegram and X. A recent leak of documents from I-Soon, a private contractor linked to China’s top policing agency and other parts of its government, described tools used by Chinese police to curb dissent on overseas social media, including one tool specifically created to surveil users on X.

Hackers also created tools for police to hack email inboxes and unmask anonymous users of X, the documents show. Sometimes, officers sent requests to surveil specific individuals to I-Soon, the leak revealed.

Li said he would not stop posting even if people unfollowed, but he urged his followers to take basic digital safety precautions.

“I don’t want your life to be impacted just because you wanted to understand the real news in China,” Li said in an additional post. “You only want to understand what’s happening, but the price is quite high.”