When it comes to official censorship, Iran doesn’t appear to distinguish friends from foes.

The Persian-language website of “Voice of Russia”-- the international broadcaster financed by the Russian government -- said in a statement that it has been blocked in Iran since February 13.

According to the statement, access to its website in Iran is now possible only by using antifiltering software and proxy sites, which Iranians use to access “blocked Western websites.”  

It didn’t mention that non-Western websites are also routinely blocked by Iranian officials and agencies in charge of online censorship.

“Voice of Russia” said it received no warning from Iranian authorities and has written to Iran’s embassy in Moscow and the Iranian Culture Ministry asking what’s behind the move.

It said the censorship could negatively affect “friendly ties” between Iran and Russia, which it notes are currently at a “high level.”

“It is particularly surprising because the Persian Service of the Voice of Russia is a government medium, and usually has a fair stance toward Iran,” the broadcaster said.

The Iranian “Entekhab” website quoted unnamed “informed sources” as saying that the likely reason behind the filtering of the Persian website of Voice of Russia is that it has not registered with Iran’s Culture Ministry.

The report said that the Persian website of the Russian news agency RIA Novosti has been active in Iran for several years without any problem.

The Islamic republic and Russia enjoy relatively good ties. In recent years, there have been some tensions between the two countries over Russia’s support for nuclear sanctions and its refusal to deliver long-range S-300 antiaircraft missiles to Iran. Russia has said that the deal violates UN sanctions imposed on Iran over its sensitive nuclear work.

Iran has complained to the International Arbitration Court in Geneva over Russia’s refusal to supply it with the antiaircraft missiles.

On February 15, Russian Deputy Foreign Minister Sergei Ryabkov was quoted as saying that “Iran cannot hope to receive the S-300 antiaircraft missile batteries that it ordered from Russia until it complies with [UN] Security Council resolutions concerning its nuclear energy program and is rewarded for this with the lifting of sanctions.”

Iran blocks tens of thousands of websites and blogs it perceives as immoral or against the country’s national interests.

Many news websites, including the website of RFE/RL’s Persian Service, “Radio Farda,” and the BBC, are also blocked.

Iranian websites and blogs are also filtered over their content. Last year, the website of former Iranian President Akbar Hashemi Rafsanjani was filtered for several weeks.