Russia has deliberately slowed down Twitter for users on its turf, following the company’s apparent refusal to remove illegal content from its platform.

The move comes against the backdrop of growing tension between the Kremlin and social media firms, particularly those from the U.S., and at a time when the imprisonment of opposition leader Alexei Navalny recently sparked large, online-organized protests.

On the face of it, however, the move by Russia’s media regulator has nothing to do with that. A week and a half ago, Roskomnadzor accused Twitter of refusing to take down nearly 3,000 tweets that discuss suicide or drug use, or that contain child sexual abuse material, and said the U.S. firm could be in line for large fines.

On Wednesday, the regulator indicated it had taken a different route. Rather than fining Twitter, it has told Russian telecoms firms to slow down its service.

And if the company still refuses to comply, it could find itself blocked entirely.

Roskomnadzor said in a statement that the count of still-available illegal tweets now stands at 3,168, the vast majority of which discuss suicide. It said Twitter, “unlike other social networks,” had not removed “calls to minors to commit mass suicide on March 3.” The authorities had stopped several minors’ suicide attempts on that day, it added.

“In order to protect Russian citizens…centralized response measures have been taken,” the regulator said, explaining that the slowdown will affect all mobile devices and half of all desktop devices.

Some Russian Twitter users have reported slow-loading user profiles and images. In what may or may not be a coincidence, Roskomnadzor’s website became inaccessible late morning, Moscow time.

Twitter had not responded to a request for comment at the time of publication; the company also did not provide any public response to Roskomnadzor’s threat at the start of March.

Kremlin animosity

Despite the regulator’s stated reasons for targeting Twitter, the service’s throttling also comes in the context of broader Kremlin animosity toward social media companies, and not just American ones.

VKontakte and Odnoklassniki, both Russian platforms, were fined millions of rubles in recent days for refusing to delete posts that urged people to join protests against Vladimir Putin’s government—Roskomnadzor has also accused Twitter, Facebook, Instagram, and TikTok of the same violation.

But the Kremlin does have a particular bone to pick with the U.S. platforms, because of their removal or labeling of Russian state propaganda. In November last year, Russian lawmakers said Facebook and Twitter could be banned for discriminating against Russian news outlets such as Sputnik and RT. Putin also recently said the U.S. platforms were too powerful.

The blockage threat is not an idle one. LinkedIn has been blocked in Russia for several years, over its refusal to store the personal data of Russian users on Russian soil. Roskomnadzor operates a sprawling blacklist and has also cracked down on the virtual private network (VPN) tools that citizens use to bypass its restrictions.

However, the censor does not always get its way. Notably, its efforts to block the messaging and microblogging service Telegram in 2018—for refusing to expose users’ conversations to the security services—quickly spiraled into farce. In its cat-and-mouse game with Telegram, Roskomnadzor accidentally blocked millions of IP addresses, hammering cloud services across the country.

Two years later, with Telegram still available to users across the country, the regulator gave up.