On the streets across several Russian cities, protesters gathered in defiance of the authorities, accusing their government of corruption.
The largest rally was in Moscow with conservative police estimates of around 8,000 people who packed into the city's central Pushkin Square.
They chanted "Russia without Putin!" and "Down with Putin!", but were met with heavily armed riot police.
The protests were unsanctioned and illegal, but demonstrators risked the prospect of arrests.
One protestor, Lyudmila, said they believed it was important to make their voices heard.
"One man cannot do anything, but a large number - they can at least show that it is impossible to live like this any longer, impossible. But I am afraid it will not be enough. I am afraid the authorities need to be hit over the head - then they maybe will realise what's happening. But so far the people are silent."
Hundreds of people were detained across the country, with at least 500 in Moscow alone, including Russia's main opposition leader, Alexei Navalny.
In chaotic scenes protestors attempted to stop the 40 year old's arrest by preventing the police van from taking him away.
And in a tweet from the van, he urged fellow protesters to continue with the demonstration.
The call to protest came following a video made by Mr Navalny and Anti-corruption Foundation about corruption linked to the prime minister, Dmitry Medvedev.
The video, which alleges that Mr Medvedev has amassed a collection of luxury mansions, yachts and vineyards, has been watched on YouTube more than 11 million times.
There's been no official reaction to the allegations.
But this protestor says it's clear who she supports.
"First of all, I'm a Navalny supporter. I think he's a fighter and a very honest man - an altruist, which is very important. I've been watching his activity for a long time and I think that the time will come that he will become our president. It's just that the time hasn't come yet."
And many are calling for Dmitri Medvedev to resign.
"If the prime minister is guilty of these lies, this corruption, all which is stated in the framework of the constitution - then of course he must be punished. How? Of course it is up to the court. But because our higher courts today are subject to this very corruption, this case will not be investigated."
Next year Russians will vote in presidential elections which President Vladimir Putin is expected to contest in what would be his fourth term.
Alexei Navalny, a lawyer by training, had announced plans to also run for the presidency after he won a surprise 27 per cent of the vote in the Moscow mayoral election in 2013.
But he has been the subject of several legal prosecutions in recent years.
In February he was found guilty of embezzlement and given a five-year suspended sentence which could make him ineligible to run in next year's vote.
