MOSCOW — The Russian government said on Wednesday that it was slowing access to Twitter, accusing the social network of failing to remove illegal content and signaling that the Kremlin is escalating its offensive against American internet companies that have long provided a haven for freedom of expression.
It was a landmark step in a country where the internet has essentially remained free despite President Vladimir V. Putin’s authoritarian rule. But it did not go off without a hitch: As media regulators tried to slow access to Twitter, dozens of Russian government websites went offline for about an hour, a crash that some experts said most likely stemmed from a technical glitch in the state’s move against the social network.
Russia’s telecommunications regulator said it was reducing the speed at which Twitter loaded for users in Russia, and pictures and videos indeed at times took longer than usual to load. The regulator, Roskomnadzor, accused the American company of failing for years to remove posts about illegal drug use or child pornography or messages “pushing minors toward suicide.”
“With the aim of protecting Russian citizens and forcing the internet service to follow the law on the territory of the Russian Federation, centralized reactive measures have been taken against Twitter starting March 10, 2021 — specifically, the initial throttling of the service’s speeds, in accordance with the regulations,” the regulator said in a statement.
“If the internet service Twitter continues to ignore the demands of the law, measures against it will continue in accordance with the regulations, up to and including blocking it,” it added.
In a statement, Twitter said it was aware of reports that its platform was “being intentionally slowed down broadly and indiscriminately in Russia due to apparent content removal concerns.”
Twitter said it had a zero-tolerance policy regarding child sexual exploitation, and did not allow the use of its platform for any unlawful behavior or to further illegal activities, including the buying and selling of drugs.
The action against Twitter, a site with a limited following in Russia, was intended as a warning to other American internet companies, Aleksandr Khinshtein, a member of Parliament who helped write a law that allowed the regulator to slow traffic, told reporters on Wednesday.
He said that putting the brakes on Twitter traffic “will force all other social networks and large foreign internet companies to understand Russia won’t silently watch and swallow the flagrant ignoring of our laws.”
The companies would have to obey Russian rules on content or “lose the possibility to make money in Russia,” he added.
Twitter — and to a much greater extent, Facebook’s Instagram and Google’s YouTube — have given Russians ways to speak, report and organize openly even though the Kremlin controls the television airwaves.
Those social networks, along with Chinese-owned TikTok, played a pivotal role in the anti-Kremlin protests that accompanied the return and imprisonment of the opposition leader Aleksei A. Navalny this year. Mr. Navalny has some 2.5 million Twitter followers, and his investigation published in January into a purported secret palace of Mr. Putin was viewed more than 100 million times on YouTube.
Russian officials claim that Silicon Valley companies discriminate against Russians by blocking some pro-Kremlin accounts while handing a megaphone to the Kremlin’s critics. They have also said that social networks have refused to remove content drawing children into the unauthorized protests in support of Mr. Navalny.
In recent weeks, the Kremlin has led an intensifying drumbeat criticizing American internet companies, painting them as corrupting foreign forces.
“Online, we bump into child pornography and child prostitution, with the sale and distribution of drugs, with children and teenagers as the target audience,” Mr. Putin said this month. The internet must respect “the moral laws of the society in which we live — otherwise, this society will be destroyed from the inside,” the president said.
Twitter has a small user base in Russia, though it is popular among journalists, politicians and opposition activists. A report last year estimated the service had 690,000 active users in Russia, meaning that any public backlash over the move is likely to be far smaller than if the Kremlin imposed similar limits for Instagram or YouTube.
The Russian government’s get-tough message to American companies, however, was blunted when soon after the announcement its own websites went offline for about an hour. Russian officials blamed an equipment failure and said the outage was unrelated to the move against Twitter.
The Ministry of Digital Development, Communications and Mass Media said in a statement that the problem with the government sites arose from an equipment failure at a state-run phone company and internet service provider, Rostelecom.
The Russian agency made the announcement in a Twitter post.
U.S. officials said over the weekend that they planned to retaliate against Russia for a sweeping hacking attack last year that exploited vulnerabilities in government and corporate computer systems in the United States. The officials said the retaliation was planned in the coming weeks, but there was no immediate evidence that Wednesday’s outage of Russian government websites was a sign of the latest volley in this cyberconflict.
Instead, commentators in Russia pointed to another possibility: that Russian regulators had bungled the job of restricting access to Twitter and inadvertently shut down government websites without any outside meddling.
“Russia’s slowing down of Twitter caused the outage,” Andrei Soldatov, a co-author of “Red Web” and an authority on Russian internet policy, said of the crash of government sites in an online post. What was meant to be in part a warning shot at American internet companies, he added, “failed on all fronts.”
While trying to shut down the messaging app Telegram in 2018, Roskomnadzor inadvertently blocked service to thousands of other websites, many belonging to small businesses that used the same web hosting services as the app. Telegram remained widely available in Russia.
Adam Satariano contributed reporting from London.