MOSCOW - The activist hacker group Anonymous said on Friday it planned to attack Russian government websites in order to support opposition protests ahead of Vladimir Putin's inauguration as president.
In an Internet video that went viral, the Russian arm of the group said on YouTube it would shut down the government's main website on Sunday, when protesters plan to stage a million-strong march in central Moscow.
This would be followed by an attack on the prime minister's website on Monday - the day of Putin's inauguration - said the message, which included instructions on how Internet users could join in.
Putin convincingly won a six-year presidential term in March despite a wave of protests following a December parliamentary poll the opposition said was tarnished by large-scale voting fraud in support of his party.
The mass rallies in Moscow and other Russian cities did not stop Putin returning to the presidency but they did strip the ex-KGB chief of the aura of invincibility that has characterised his 12-year rule, first as president then as prime minister.
"On the 6th of May, there will be mass demonstrations against the illegitimate elections. We will support this protest by shutting down the lying government's sites," Anonymous said in the YouTube message.
"If you did not elect these authorities and you are against a self-elected president crowning himself for a third time, join us."
It said it would launch attacks on the Russian government website Government.ru at 1200 GMT on May 6 and on the prime minister's website Premier.gov.ru on May 7 at 0900 GMT.
Anonymous hacked into the emails of a pro-Kremlin youth organisation earlier this year, in what it said was a response to a growing number of hacker attacks by pro-government groups on independent news outlets and opposition bloggers.
Both sides are turning to increasingly accessible technology that can be used for hacking to find more and more people willing and able to carry out cyber attacks, according to a recent report from Britain-based human rights advocacy website OpenDemocracy.
Moscow has called for a globally binding UN treaty on cyber security to crack down on Web crime.
Western countries have balked at the proposal but highly-publicised attacks by hacker groups Anonymous and LulzSec, including against US and British government websites, have highlighted the Internet's vulnerabilities.