Russia's blogosphere reacted with anger today after a regional court banned YouTube because it carried a single video containing "extremist" content.

The court in Komsomolsk-on-Amur in Khabarovsk region in the Russian far east ordered Rosnet, a local internet provider, to block YouTube as well as three online libraries and a website that archives deleted web pages.

The regional ban was made because YouTube hosted Russia For Russians, an ultra-nationalist video which was added to the justice ministry's federal list of banned extremist materials after a separate court decision in Samara region in November.

The other four sites – Web.archives.org, Lib.rus.ec, Thelib.ru and Zhurnal.ru – all carried copies of Hitler's Mein Kampf.

Anton Nosik, Russia's leading internet guru, condemned the decision. "The level of crassness in this court ruling is typical of legal proceedings concerning the internet in Russia," he said. Google, the owner of YouTube, said the ruling violated Russians' constitutional right to freedom of information.

Many bloggers also decried the ban, warning it could be a slippery slope to tighter censorship across the country.

"I can imagine it now," wrote Ghost82 on LiveJournal. "Russia in 2015, YouTube is banned everywhere. In search of a gulp of air, people travel to the border with Georgia where they will sit with their laptops and pay unimaginable sums to connect to the internet via powerful Wi-Fi transmitters for a taste of depraved western civilisation."

Alexander tweeted on RuTvit: "YouTube has been given to understand that Russia, Pakistan and North Korea have much in common."

An engineer with Rosnet said the company had suggested prosecutors should contact the portals concerned directly to request they take down the offensive material, rather than issuing a blanket ban. "They [prosecutors] remained deaf to these pleas," he told the Gazeta.ru news website. Rosnet is appealing the ruling.

While television is tightly controlled by the state, Russia's soft authoritarian government has so far done little to rein in the internet. Social media and blogging sites are popular and provide a vital outlet for opposition and civil movements.

However, a package of laws to be reviewed by parliament in October could give the security services new powers to close down sites at short notice.

The YouTube ruling is likely to be an embarrassment for President Dmitry Medvedev, who recently launched his own channel on the video-sharing site.

Other countries that have banned YouTube include China, Pakistan, Turky and Iran.