The Kremlin has responded to mass protests on Sunday by accusing the opposition of encouraging lawbreaking and provoking violence.
Some young people were paid, a presidential spokesman said, but added that the message from legal protests would be listened to.
Defiant Russian opposition leader Alexei Navalny, one of hundreds detained, appeared in court on Monday.
He repeated accusations of corruption against PM Dmitry Medvedev.
The allegations were the main reason behind Sunday’s protests, which drew thousands of demonstrators nationwide, including in Saint Petersburg, Vladivostok, Novosibirsk, Tomsk and several other cities, as well as Moscow. At least 500 protesters were detained.
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Kremlin spokesman Dmitry Peskov, in the first comments by the presidency since the protests, said: “Essentially what we saw yesterday in several places – probably especially in Moscow – is a provocation and a lie.”
He said young people had been “promised financial rewards in the event of their detention by law enforcement agencies”.
Mr Peskov praised the “appropriate, highly professional and legal” response of the security forces and dismissed calls from the European Union on Monday that those detained should be released “without delay”.
Before his court appearance, Mr Navalny, 40, tweeted from the building: “Hello everyone from Tverskoy Court. The time will come when we will have them on trial (but honestly).”
He argued it was Mr Medvedev who should be was summoned as the chief organiser of the protests, because his “corrupt activities led to people coming on to the streets of 99 Russian cities”.
Mr Navalny also said he wanted those detained to be given the opportunity to take their cases to the European Court of Human Rights.
He faces charges relating to organising banned protests and could be held for 15 days. The court has yet to rule.
Correspondents say the marches appear to be the biggest since anti-government demonstrations in 2011 and 2012.
What have the EU and US said?
An EU spokesman said the Russian police action had “prevented the exercise of basic freedoms of expression, association and peaceful assembly, which are fundamental rights enshrined in the Russian constitution”.
The statement added: “We call on the Russian authorities to abide fully by the international commitments it has made… and to release without delay the peaceful demonstrators that have been detained.”
US state department spokesman Mark Toner said in a statement: “The Russian people, like people everywhere, deserve a government that supports an open marketplace of ideas, transparent and accountable governance, equal treatment under the law, and the ability to exercise their rights without fear of retribution.”
What are the protests about?
Mr Navalny called for the nationwide protests after he published reports claiming that Mr Medvedev controlled mansions, yachts and vineyards – a fortune that suggests income that far outstrips his official salary.
His report, posted on YouTube, has been viewed more than 11 million times.
It includes the accusation that Mr Medvedev had a special house for a duck on one of his properties – and on Sunday, some demonstrators held up images of yellow rubber ducks.
Others showed up with their faces painted green, a reference to a recent attack in which Mr Navalny was hit with green liquid.
Mr Medvedev’s spokeswoman called the allegations against him “propagandistic attacks”.
When asked how he spent Sunday, the prime minister said simply on Instagram: “Had a good day, I went skiing”, and posted a smiley face.
Who is Alexei Navalny?
The most prominent critic of President Putin, Mr Navalny began his anti-corruption campaign with blogs aimed at state-controlled companies in 2008.
He moved on to opposing the ruling party, United Russia, calling it the “party of crooks and thieves”.
He led massive protests following the 2011 election, the biggest in Moscow in December that year, after which he was arrested and jailed for 15 days.
He has said he will run for the presidency in 2018, but a court has convicted him of embezzlement, which would bar him. He denies the charges, calling the case farcical.
What have the media said?
Russian state television completely ignored the protests on Sunday. Monday morning’s bulletins were similarly blank.
Pro-Kremlin newspapers also ignored the protests.
But the BBC’s Steve Rosenberg in Moscow says there was coverage in some others. Business daily Vedomosti reported a high level of dissatisfaction with the authorities, saying that the young generation had become politicised.
Another paper refers to “Putin’s disastrous anniversary” – the protests coming 17 years after the president took office – and says: “A few months ago, Alexei Navalny was seen as yesterday’s man who’d missed the bus. He hasn’t missed any bus.”
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