By Ian Bateson
MOSCOW, Feb 28 (Reuters) - A Russian court placed opposition leader Alexei Navalny under house arrest for at least two months on Friday and barred him from using the Internet or speaking to the media.
The court said Navalny, an outspoken critic of President Vladimir Putin and a leader of anti-Kremlin protests in 2011 and 2012, had violated rules barring him from leaving Moscow.
Navalny denounced the ruling as baseless and said it was meant to silence him. Supporters, including members of protest band Pussy Riot, shouted "Freedom!" as he left the courtroom.
"I believe the new measures are based on trumped up grounds in order to restrict my political activities," Navalny, 37, said in court.
Kremlin opponents say the upheaval in neighbouring Ukraine, where protests forced President Viktor Yanukovich from power after he scrapped plans for closer European Union ties to move closer to Moscow, has deepened Putin's determination to prevent any revival the earlier street demostrations.
They say Putin is also clamping down on dissent after engineering the release of long-jailed oil tycoon Mikhail Khodorkovsky and two members Pussy Riot before the Sochi Olympics, which ended last week.
Navalny, who gained prominence with blog posts alleging government corruption, emerged from the biggest protests of Putin's 14-year rule as the main opposition leader and a potential future challenger in elections.
He is serving a five-year suspended sentence on a theft conviction that will keep him out of a 2018 presidential vote, and has been charged with theft and money-laundering in a separate case that has not come to trial.
Navalny was one of hundreds of people detained on Monday at protests against the jailing of seven activists convicted of rioting and attacking police at a demonstration against Putin on the eve of his inauguration to a six-year third term in 2012.
Lawyers and relatives of those activists say they believe the jail sentences, ranging from two-and-a-half to four years, were a signal from the Kremlin that it will act firmly to prevent any repeat of the Ukraine events in Russia.
Putin denies he uses the courts as a political tool and has shrugged off criticism over what Western governments see as a measures restricting freedoms such as speech and assembly during his new term.
Prosecutors said Navalny had informed the authorities of trips with his wife and children into the region than rings the capital only after the fact, and the judge agreed that was a violation. Navalny denied he had done anything wrong and said his anti-corruption work would continue without him.
Under the terms of his house arrest, which expires on April 28 but is renewable, he is barred from using the Internet and telephone and can only speak to close relatives, his lawyers and the authorities, his spokeswoman Anna Veduta said on Twitter.
The measures were imposed in connection with a case in which Navalny and his brother are charged with stealing 26 million roubles ($720,000) from a Russian affiliate of French cosmetics firm Yves Rocher and 4 million roubles from another firm through fraud, and of laundering 21 million roubles. He denies guilt. ($1 = 36.1655 Russian roubles) (Reporting by Ian Bateson, Writing by Steve Gutterman, Editing by Angus MacSwan)