Russian opposition leader Alexei Navalny has been jailed for 15 days for resisting police orders during mass protests on Sunday.
Mr Navalny was among several hundred people who were detained in connection with the rallies across the country.
The court in Moscow earlier fined him the minimum 20,000 roubles ($350) for organising the banned protests.
On Monday the Kremlin accused the opposition of encouraging lawbreaking and provoking violence.
Some young people were paid to attend, a presidential spokesman said.
Mr Navalny later repeated accusations of corruption against Prime Minister Dmitry Medvedev.
The allegations were the main reason behind Sunday's protests, which drew thousands of demonstrators nationwide, including in St Petersburg, Vladivostok, Novosibirsk, Tomsk and several other cities, as well as Moscow.
While Moscow police reported earlier that 500 people had been detained, the OVD-Info human rights group said 1,030 people had been detained in Moscow and that at least 120 of them were still being held.
An autocrat with the consent of the governed, Putin has preserved the essential personal freedoms that the Russian people first earned with the demise of the Communist system. People can worship and travel freely; Facebook and Twitter are essentially unrestricted; there are even a few tolerated media outlets overtly in opposition to the Kremlin. Political freedoms, however, are more tightly circumscribed, so as to leave no chance to potential “colour revolutionaries” or politically ambitious exiled oligarchs. For the bulk of the population, this matters little; the relatively few activists have a choice of taking it – or leaving.