After Facebook, Russia has now blocked Twitter to stifle the flow of information as its invasion of Ukraine escalates.
Twitter said it is aware of the restriction being imposed on the platform in Russia.
"We're aware that Twitter is being restricted for some people in Russia and are working to keep our service safe and accessible," Twitter said in a tweet late on Saturday.
Internet monitoring group NetBlocks saw failed or heavily throttled connections across every major Russian telecom provider, including Rostelecom, MTS, Beeline, and MegaFon.
Russians are still able to access Twitter through VPN services, but direct connections are restricted, reports The Verge.
"We believe people should have free and open access to the Internet, which is particularly important during times of crisis," said Twitter.
Hit by partial restrictions, Meta (formerly Facebook) on Saturday said it is prohibiting Russian state media from running ads or monetising on its platform anywhere in the world.
The additional steps in response to Russia's invasion of Ukraine came after the country began to "partially restrict" access to Facebook.
Meta earlier criticised Russia's move to restrict Facebook in the country, saying that it reacted in response to either Facebook's fact-checking practices and its policy of labelling state-run media accounts.