At least 15,000 people turned out at a peaceful demonstration in Moscow’s Pushkin Square Tuesday demanding democratic reforms and denouncing President Vladi­mir Putin. The event was symbolically held on a national holiday that commemorates the Russian republic’s declaration of sovereignty.

The protesters chanted “Russia without Putin,” and appeared to represent a variety of political parties and groups:

Photoblogger Ilya Varlamov was tweeting from the event, saying protesters were also chanting “new election” as they waved red flags.

Russia’s Interior Ministry said 70,000 police officers and 9,000 soldiers would be mobilized in cities across the country Tuesday for added security, but they kept a low profile as the march in Moscow began, according to Post reporters Kathy Lally and Will Englund.

‘Cool. My house is being searched.’

Tuesday’s protests were the latest in a series of demonstrations fueled by outrage over political corruption and Putin’s continued hold on power. The Post’s Kathy Lally reported Monday:

“The protest movement coalesced in December over anger at parliamentary elections that were described as rigged. Those elections were followed by March’s presidential vote, which put Putin back in the office for a six-year term. He had been prime minister after two earlier four-year terms as president.”

The previous major protest occurred May 6, the eve of Putin’s inauguration, and it turned violent, with police striking protesters with nightsticks and detaining more than 450 people.

The opposition gathering on Tuesday drew a mix of liberals, socialists, nationalists, environmentalists and others. A few regulars are anti-corruption blogger Alexei Navalny, Left Front movement leader Sergei Udaltsov, and Ilya Yashin, a 28-year-old leader in the liberal opposition. Kseniya Sobchak, the daughter of former Saint Petersburg mayor and Putin mentor Anatoly Sobchak, has also recently joined the protests and spoke out against Putin’s re-election. All four were called for questioning by police an hour before the protest was scheduled to begin, but Udaltsov said on Twitter that he would go to the protest instead.

The government has taken a number of recent steps that members of the opposition believe are meant to discourage the rallies and to demoralize participants.

Last week, the Russian legislature passed a bill that would raise fines for unsanctioned protests from 2,000 rubles to 300,000 ($9,000) for people taking part in unsanctioned rallies or violating the terms of permits issued for public gatherings.

Police searched the apartments of several Russian activists Monday morning.

Navalny said on Twitter that his home was searched for more than 9 hours, and he tweeted updates and photos along the way:

Круто. У меня дома идет обыск. По делу о массовых беспорядках. Чуть дверь не распилили. (на самом деле да)

— Alexey Navalny (@navalny) June 11, 2012

“Cool. My house is being searched. On account of massive riots. They nearly sawed the door off (not kidding).”

Sobchak tweeted that police called her for questioning before the demonstration started:

И конечно на допрос по делу о организации беспорядков вызвали в 11утра завтра.чтоб не дай бог не пошла в 12 на митинг #большеадабытьнеможет

— Ксения Собчак (@xenia_sobchak) June 11, 2012

“Of course I’m in for questioning on charges of organizing riots at 11 a.m. tomorrow. God forbid I go to the noon meeting”

Udaltsov seemed emboldened by the raid:

Друзья! Завтра для всех нас проверка. В ответ на обыски и аресты на Марше нас должно быть ОЧЕНЬ МНОГО! Ждем всех в 12.00 у к/т Пушкинский.

— Сергей Удальцов (@s_udaltsov) June 11, 2012

“Friends! Tomorrow will be a check for all of us. In response to searches and arrests there must be VERY MANY of us at the march. We look forward to seeing everyone at 12:00 in Pushkin.”

@WakeUpR, the handle of the opposition For Fair Elections umbrella group, tweeted a photo of Navalny saluting journalists and bystanders with a raised fist during the police search. It followed with a call to meet at Pushkin Square Tuesday at noon.

During a televised news conference, Yashin said he and fellow organizers of the protests were undeterred by threats of fines :

“On the 12th of June, we will go out no matter what. If we incur fines, we will raise money on the Internet to pay for these fines,” he said in a clip aired on the Channel One news station.