Russia's internet monitoring agency has blocked 13 web pages with links to the Ukraine Maidan protest movement which removed president Viktor Yanukovich last week.
The Federal executive body responsible for control and supervision in the media, called Roskomnadzor, said it had been ordered by the general prosecutor's office to ban the pages on Russia's VKontakte, which is the country's most popular social media and the second biggest social networking service in Europe after Facebook.
The agency said the groups "propagandised the activity of Ukrainian nationalist groups" and accused them of emboldening "terrorist activity" and "participation in unsanctioned mass actions".
The largest pro-Maidan group with more than 500,000 members, was inaccessible to users in Russia on Monday.
Russia's crackdown on Ukrainian netizens took place days after a Russian court's ruling on the country's most popular anti-Putin blogger, Alexei Navalny.
The anti-corruption campaigner was given a two-month house arrest for repeatedly travelling outside Moscow in breach of an undertaking not to do so.
Navalny who will be banned from using any communication devices and the internet, is serving a five-year suspended sentence for taking part in the embezzlement of 16 million roubles (£300,000) worth of timber from a state-owned company, while working as an adviser for the governor of the region four years ago.
The internet ban means that Navalny will not be able to update his popular LiveJournal anti-corruption blog and the Facebook/Twitter pages.