Russia has disrupted Twitter's services because the platform had failed to remove "illegal" content, the government said, the latest of a series of moves to exert control over foreign tech giants.
The Russian government has been clamping down on sites including Facebook, Twitter and YouTube in recent months for hosting content supporting jailed opposition figure Alexei Navalny.
Roskomnadzor, Russia's media watchdog, said the disruption of Twitter was intended to "protect Russian citizens" after the platform failed to comply with thousands of requests to delete content related to child pornography, drug use and calls for minors to commit suicide.
The watchdog did not reference .
Roskomandzor said the disruption would amount to a "slowdown in service speed" for all mobile users and 50 per cent of desktop users, later adding that it would only affect photo and video content.
Opposition leader Alexei Navalny at Babuskinsky District Court in Moscow. Source: AP
Officials accused foreign internet companies of interfering in Russia's domestic affairs in January over their failure to take down calls to participate in rallies in support of Mr Navalny.
President Vladimir Putin then warned against the increasing influence of large tech companies, saying they were "competing" with sovereign states.
The watchdog warned that if Twitter ignored Russian law it could face further restrictions, including a complete ban.
Kremlin spokesman Dmitry Peskov insisted Russia had "no desire to block anything" and said the measures forcing companies to comply with Russian laws were "quite reasonable".
According to tech monitoring website Downdetector there was a spike in disruptions reported by Russian Twitter users on Wednesday morning.
Twitter did not immediately respond to a request for comment.
Facebook 'next'
Politicians on Wednesday welcomed the regulator's decision, warning that other social networks may be next.
"I am sure Twitter will lose big money," said Anton Gorelkin, a politician on a parliamentary telecommunications committee.
He told the Interfax news agency that Facebook could be the "next candidate" for restrictions.
Another politician Alexander Bashkin said the decision would be "sobering" for YouTube and other platforms.
Moscow also recently raised concerns about the Chinese video sharing app TikTok that was flooded with calls to demonstrate in support of Mr Navalny in January.
Russia's government has spent years tightening its control over the internet in the name of fighting extremism, terrorism and protecting children.
Officials have repeatedly fined Google for failing to remove content and last year fined Twitter and Facebook for refusing to store the personal data of Russian citizens on local servers.
A 2019 law proposes a "sovereign internet" aimed at isolating the country online, a move activists fear will tighten government control of cyberspace and stifle free speech.
Moscow has already banned a number of websites that refused to cooperate with authorities, such as video platform Dailymotion and professional networking website LinkedIn.
Politicians also attempted to block the Telegram encrypted messaging service but lifted the ban because it was not being fully enforced.
