Tens of thousands of people took to the streets across Russia against Vladimir Putin's 12-year rule amid signs of swelling anger over a poll won by his ruling United Russia party.
The protesters on Saturday demanded an end to Putin's rule and a rerun of the parliamentary election in the biggest popular protests since those that led to the fall of the Soviet Union.
Protesters waved banners, such as "The rats should go!" and "Swindlers and thieves - give us our elections back!", in cities from the Pacific port of Vladivostok, Perm in Siberia, Arkhangelsk in the Arctic north, in Kaliningrad and St Petersburg in the west, and Karelia in the northwest.
"Nationwide there have been protests in dozens of towns and cities, all across Russia's nine time zones," Al Jazeera's Neave Barker, reported from Moscow.
"They're calling not for revolution, but for political evolution," he said.
'End of aquiescence'
In Moscow, people gathered on Bolotnaya Square, on an island across the Kremlin after receiving permission from the authorities for the event.
Police said there were at least 25,000 at the Moscow demonstration, while protest organisers claimed more than 60,000 were present.
Opposition leader Mikhail Kasyanov, who took part in the protest, said the Russian public "have run out of patience" with the current government.
"Especially in large cities where people are well-educated, well-informed who understand they are not ready to tolerate such lawlessness when they are ignored and their votes are cynically stolen," Kasyanov, who is also a former Russian prime minister, said.
Authorities had detained about 1,600 activists over the past few days who had joined unsanctioned rallies against the December 4 vote.
The rallies were a rare outpouring of mistrust in a system put in place by Putin when he first became president in 2000.
Konstantin Kosachyov, a United Russia lawmaker authorised to speak on behalf of the Kremlin, ruled out
negotiations on the organisers' demands and said: "With all respect for the people who came out to protest, they are not a political party."
The authorities' decision to permit Saturday's rallies to go ahead nationwide is a first for the Putin-era and suggests the Kremlin would prefer to avoid street battles between protesters and riot police.
"Faced with this kind of opposition, it was very important for the authorities to show that they were allowing some kind of controlled dissent," our correspondent reported.
Speaking to Al Jazeera, Ivan Safranchuk, a Russian political analyst, said: "People will be allowed to protest, but direct political change won't happen."
For Fred Weir, who has been a Moscow correspondent for The Christian Science Monitor for 25 years, the protests recalled the historic demonstrations of 1991.
"What we're seeing here is a game changer," he said. "He'll [Putin] have to take into account that the public mood is no longer acquiescent," he said.
Alexey Zakharov, a political analyst in Moscow who is part of an independent organisation called "Citizen Oberserver" which monitored the recent vote, said the protests were "quite a serious threat" to Putin.
Putin was only accepted by Russia's elites in large part because of his genuine popularity among the people, Zakharov said.
"The public will turn out to demonstrate if they believe the opposition is honest with them," he said, "If its not going to strike any side deals with the Putin administration."
Putin's United Russia has been bruised by allegations of corruption, after opposition parties and international observers said the vote was marred by vote-rigging, including alleged ballot-box stuffing and false voter rolls.
|A map of protest locations in Moscow on Saturday
The official results of the elections to Russia's Duma showed that the ruling party United Russia lost 77 of its 315 seats, just retaining a small majority.
Barker said there is a widespread view, fuelled by mobile phone videos and accounts on internet social networking sites, that there was wholesale election fraud, and that Putin's party cheated its way to victory.
Putin accepted the vote's outcome but stayed silent about the protests for three days before accusing US secretary of state Hillary Clinton of inciting the unrest by questioning the polls.
He said Clinton's criticism "had set the tone for some people inside the country and given a signal".
Mark Toner, a spokesperson for the US state department, retorted that "nothing could be further from the truth".
Putin has remained Russia's most popular and powerful politician as both president until 2008 and prime minister today - an image he has cultivated with tough talking against foreign powers and warm words for the Soviet past
"I want new elections, not a revolution," Ernst Kryavitsky, 75, a retired electrician dressed in a long brown coat and hat against the falling snow who was protesting in Vladivostok.