Russians across the country were unable to access websites with the local .ru domain on Tuesday evening, with authorities blaming the mass disruption on technical problems.
Users also reported that their banking apps were not working and that social networks, online retailers, government service portals and news sites were also unavailable.
Russia's ministry of digital development blamed tech issues that would soon be resolved.
But no specific reason was given for the failure, which was felt in several parts of Russia. Sites without the .ru domain, however, were often still accessible.
Independent tech experts have warned that plans under way by Moscow to create an independent Russian internet, which attempts to bypass infrastructure that manages global web traffic, can lead to outages and interruptions to service.
In Moscow, for example, disorientated taxi drivers frequently complain about navigation systems that do not work properly. Social networks WhatsApp and Telegram have also suffered outages in Russia.
There is also direct government censorship of thousands of websites that contain content that does not conform to the views of the state.
