Prime Minister Vladimir Putin said on Thursday he was pleased by Russia's outburst of protests against his 12-year rule but rejected opposition claims that parliamentary elections were rigged.

In his annual phone-in session with Russians, Putin sought to show he was relaxed about the mass protests alleging fraud in the December 4 parliamentary elections won by his United Russia party.

"I saw on television mostly young, active people clearly expressing their positions. I am pleased to see this," Putin said in his first reaction to the demonstrations.

"And if this is the result of the Putin regime, than this is good. I see nothing extraordinary about it."

Tens of thousands of people protested on Saturday in Moscow in a sanctioned protest that was Russia's biggest show of popular discontent since the turbulent 1990s. The rally was peaceful although protests earlier in the week ended in hundreds of arrests.

"The fact that people are expressing their point of view about the processes occurring in the country, in the economy, in the social sphere, in politics, is an absolutely normal thing, as long as people continue acting within the law."

"I expect them to continue doing so," he added. The ruling party United Russia won the parliamentary elections but with less than half the vote, a result the opposition said would have been far worse had the polls been free.

The protests have shaken Putin's domination of Russia just as he is preparing to return to the Kremlin in March elections that now appear a trickier proposition than before.

But with the new State Duma lower house of parliament due to meet next week, Putin insisted that the results were realistic.

"In my opinion, the result of these elections unquestionably reflects the real political make-up of the country," said Putin.

"As for the fairness or unfairness: the opposition will always say the elections were not fair. Always. This happens everywhere, in all countries."

But Putin also took the opportunity to mock the protesters, saying he thought white ribbons worn as a symbol of their demonstrations against his rule were contraceptives in an anti-AIDS campaign.

"I decided that it was an anti-AIDS campaign... that they pinned on contraceptives, I beg your pardon, only folding them in a strange way," Putin said.

He also alleged that some of the participants were hired to protest against the government.

"I know that students were paid some money -- well, that's good if they could earn something," he said. Putin last week accused US Secretary of State Hillary Clinton of encouraging the Russian opposition to protest by sending them a signal.

But in an apparent bid to calm the claims of fraud, Putin ordered the installation of web cameras in every Russian polling station.

"I ask the central election commission to install web cameras in all 90,000 polling stations in the country and put the footage on the Internet so the whole country can see," he said.

Putin said Russia's political system would be strengthened in all areas should he return to the presidency for a historic third term after 2012 elections. 'This will be my goal, if the country gives me this work.'

The carefully stage-managed annual phone-in, which allows Putin to flaunt his charisma and a natural ability to command attention, is designed to boost his image and show he remains in control of Russia.

Outgoing President Dmitry Medvedev, who in September agreed to step aside for Putin after just one term in office, has never held phone-in sessions with Russians since he entered the Kremlin in 2008, instead choosing a safer format of a television interview.