Ukraine on Tuesday blocked popular Russian social networks and an internet search engine as it expanded sanctions against the Kremlin for its alleged backing of a three-year war in the separatist east.
President Petro Poroshenko signed a decree banning access to VK -- often referred to as Russia's Facebook -- and Ukraine's version of the popular Yandex search engine.
It also cut access to the Mail.ru email provider, the Odnoklassniki (Classmates) social network as well as the Moscow-based Kaspersky Lab cybersecurity and anti-virus provider.
The bans apply for three years.
Kiev has been gradually expanding its list of banned Russian products and people forbidden from entering the country for either voicing support for the Kremlin's March 2014 annexation of Crimea or the self-proclaimed independence of Ukraine's east.
Numerous Russian movies and television series have been forbidden. The ban also covers some books.
The West strongly supports Kiev's assertion that Russia has both plotted and backed the insurgency in the eastern industrial regions of Lugansk and Donetsk that has claimed more than 10,000 lives.
The war began less than two months after massive street protests toppled a Russian-backed president in February 2014 and both Kiev and the West see the conflict as Russia's retribution for the loss of its ally.
But human rights groups have voiced criticism of Ukraine's decision to apply its sanctions against various forms of cultural entertainment as a violation of free speech.
The immediate reaction to Poroshenko's decision in Ukraine itself was strongly negative.
"Hello, North Korea," 112 rolling news channel editor Vitaliy Prudyus wrote on Facebook.
VK, formerly known as VKontakte, is Russia's most popular social network. Its official Ukraine page wrote in February that it gets 16 million unique visitors daily in Ukraine.
The sanctions already in place nearly overshadowed the Eurovision Song Contest that concluded at the weekend in Kiev.
Ukraine banned Russia's contestant for staging a performance in Crimea a year after its annexation.
Russia responded by refusing to air the kitschy competition and organisers have warned Ukraine that it may be forbidden from taking part in upcoming events for its actions.