The popular website Chess.com has been blocked in Russia after publishing two critical articles on the situation in Ukraine branded "false information" by the authorities.
The site, which boasts 50 million members worldwide, is now on a list of blocked sources drawn up by Russia's telecom watchdog Roskomnadzor.
The general prosecutor's office requested that access to just two pages of the Chess.com critical of Russia's "special operation" in Ukraine be restricted, domestic agencies and media reported.
But because Chess.com uses the HTTPS protocol, the whole site has become unavailable, the media said.
Chess.com could not be opened in Russia on Sunday afternoon.
The articles allegedly condemned the offensive Russia unleashed in Ukraine on February 24, according to Russian media reports.
Chess.com has already banned Russian grandmaster Sergey Karjakin, who has publicly supported the offensive, from playing games on the site.
Karjakin, who played Norway's Magnus Carlsen in 2016 for the world title, has also been suspended for six months by world chess governing body FIDE.
This month he called for Chess.com to be blocked, accusing it of "anti-Russian choices" and "insulting propaganda".
Karjakin took to the Telegram messaging service to praise the move against Chess.com by the Russian government.
"Is it really a great loss for Russian-speaking users?" he asked, adding, "Not in my opinion."
"Once again we are witness to a situation where Western platforms lose their Russian public because of their own phobia of Russia."
Social networks such as Twitter, Facebook and Instagram have already been blocked in Russia, as have dozens of media websites over Ukraine.
Since President Vladimir Putin sent troops to Ukraine, authorities have stepped up measures to silence critics of the military operation in Russia's pro-Western neighbour.
New legislation imposes prison terms of up to 15 years for spreading information about the Russian military deemed false by the government.