Russia threatened Tuesday to block the website of the BBC's Russian Service because it reported an activist's public appeal to get people to attend a rally mocking Moscow's policy in Ukraine.
The BBC last week ran an interview with Artyom Loskutov -- an artist who has developed a reputation for performances that poke fun at the Kremlin -- promoting a demonstration in favour of giving Siberia more rights within Russia.
The idea had been making the rounds in opposition circles for weeks because it offered a seemingly legal way to mock Moscow's call for decentralisation in Ukraine to support ethnic Russians there while keeping tight control at home.
Russian authorities under President Vladimir Putin often ban anti-Kremlin rallies and arrest or fine their organisers.
The Kremlin wants Ukraine transformed into a federation in which Russian-speaking regions in the industrial east have broader rights and are able to establish their own trade and diplomatic relations with Moscow.
Ukraine's new pro-Western leaders have rejected the idea and accuse Putin of seeking to strip Kiev of direct control over the volatile region.
The BBC World Service in London said it had "no plans to remove the interview" because it helped "bring out serious issues about life in Russia".
- 'Unconstructive stance' -
Russia's Roskomnadzor media watchdog said the general prosecutor's office had earlier asked it to stem the flow of information about the proposed event seeking greater rights for the Siberia region within Russia.
The agency said in a statement that it had "repeatedly sent" notices to the BBC Russian Service and accused its website of purposely ignoring state orders.
"If the editorial staff of the BBC Russian Service, unlike most other Russian media, continues assuming an unconstructive stance, Roskomnadzor will have no alternative... but to block the BBC Russian Service website."
The regulator had already denied online access to the interview and told Izvestia -- a pro-Kremlin daily that broke the news in its Tuesday edition -- it had the technical means to restrict access to the site across Russia.
Izvestia said Russian officials believed Loskutov's call on people to attend the "March for a Federal Siberia" threatened "the territorial integrity of the country".
- A 'parody' rally -
The BBC Russian Service said in a blog post that editors had added an introduction to the interview featuring the artist's own description of the event as nothing more than a "parody" that in no way promoted Siberia's independence from Moscow.
A spokesman for the BBC World Service in London added that its Russian site's July 31 broadcast of the audio interview with Loskutov was in full compliance with its editorial policies.
"The BBC aims to present all sides of a story in an impartial, unbiased way, and we have also requested an interview with a Russian government official to explain their position on the planned march," the spokesman in London said.
The BBC's various Russian services have suffered since the 2006 poisoning in London of a prominent Moscow-based critic of Putin that British authorities suspect may have been carried out by acting and former Kremlin security agents.
The BBC was forced to shutter its radio broadcasts -- jammed by authorities back in Soviet times, and criticised heavily under Putin -- in 2011 after being dropped by many of its Russian partner stations.
The European Union and United States have imposed punitive sanctions on Russia for the seizure of Crimea and its support for pro-Kremlin insurgents in eastern Ukraine.
The sanctions threaten to tilt the already weak Russian economy into recession and further underscore the degree to which Moscow's diplomatic isolation has grown under Putin's 15-year rule as both president and prime minister.