See below for videos.

Update, 12:33 a.m.: Tuesday night, Moscow police clashed with anti-Putin demonstrators outside the Tchaikovsky Concert Hall downtown. An AP reporter reportedly saw at least two firebombs thrown into a crowd; those later turned out to be flares. Police have arrested as many as 300 people who defied the rally ban, including journalists.

Update, 10:20 a.m.: An earlier version of this post reported troops moving into Moscow Tuesday after anti-government protests. Troops had been in Moscow since before Sunday’s parliamentary elections.

Thousands of people gathered in this capital Monday night to protest Sunday’s surprisingly controversial parliamentary elections, shouting “Russia Without Putin” and “We Need New Elections.”

The Interior Ministry had brought more than 50,000 troops into Moscow for the election weekend, and they remained on the alert. Some took up posts around locations where demonstrations are usually held.

Police officers detain an opposition activist during a protest against vote rigging in St.Petersburg, Russia. (Dmitry Lovetsky/AP)

Popular blogger Alexey Navalny was arrested with nearly other 300 people around Chistye Prudy, a park and metro station. From the riot police van, he tweeted an image of a crowd of men grinning. Navalny wrote, “I sit with the boys on the riot police bus. They all convey greetings.”

The police put the number of people at the Chistye Prudy protest Monday at 700, but reporters estimated that there were at least 5,000 people there.

They came both to show their fatigue with Prime Minister Vladi­mir Putin and his United Russia Party and to protest against election misconduct — independent monitors reported lots of ballot stuffing and other violations.

A counter-demonstration of young people shouting in support of United Russia and Putin gathered near the Kremlin Tuesday afternoon (Moscow is now nine hours ahead of Eastern Standard Time).

All the shouting was set off by United Russia’s huge loss of support Sunday — it got just under 50 percent of the vote, compared to 64.3 percent in the 2007 parliamentary elections. And that’s with the election irregularities — something U.S. Secretary of State Hillary Rodham Clinton harshly criticized two days in a row.

Putin was not up for election this time, and he’s considered the strongest candidate for reelection in March. However, his party’s diminished showing at the polls is seen as a strong criticism of his government.

A number of videos appeared on YouTube purporting to show election fraud. The Atlantic Wire reports that as Secretary of State Hillary Clinton calls for a full investigation of the elections, “YouTube might be the best place to look for evidence.”

Watch as one man confronts an election official who appears to be filling out a stack of ballots:

In the following video, a group of paid ballot box stuffers are shown reportedly fleeing an election station:

Here, Russian election officials are shown supplying voting stations with erasable pens:

And finally, this video from YouTube user ATEISTGNOOM, reportedly shows bundles of ballots “stacked flat,” a sign that could have been stuffed into a ballot box together instead of by individual voters:

Further Reading:

A Russian Spring? The Washington Post editorial board thinks so

See a gallery of Russian election photos

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