Protesters reference Stalin as thousands gather to protest Putin's rule

June 12, 2012: Protesters carry a banner reading, "Russia Go Forward without Putin" during a demonstration in Moscow.

June 12, 2012: Protesters carry a banner reading, "Russia Go Forward without Putin" during a demonstration in Moscow.  (AP)

Thousands of Russians are gathering Tuesday for the first massive protest against President Vladimir Putin's rule since his inauguration as investigators summoned several key opposition figures for questioning in an apparent bid to disrupt the rally.

Anti-corruption blogger Alexei Navalny, leftist politician Sergei Udaltsov, liberal activist Ilya Yashin and TV host Ksenia Sobchak were called for interrogation by the Investigative Committee just an hour before thousands of protesters were to gather for a march across downtown Moscow.

The interrogation session would make it hard, if not impossible, for them to appear at the rally, and it follows searches of their apartments Monday that were described by some as a crude attempt by the government to derail the protest.

Udaltsov snubbed the summons, saying on Twitter that he considers it is his duty to lead the protest as one of its organizers. He may now be arrested.

Braving a brief thunderstorm, thousands of protesters showed up on the iconic Pushkin Square ahead of the planned march.

"Those in power should feel this pressure, we will do this by no means no matter what are the methods, peaceful or not," said Anton Maryasov, a 25-year-old postgraduate student. "If they ignore us that would mean that the bloodshed is inevitable."

The investigators' action follows a quick passage last week of a new bill that will raise fines on those who take part in unauthorized protests 150-fold, to nearly the average annual salary in Russia.

The top Twitter hashtag in Russia on Monday was "Welcome to the Year `37," a reference to the height of the purges under Soviet dictator Josef Stalin.

Tuesday's protest has city approval, but any shift from the agreed upon location and timeframe could give police a pretext for a crackdown.

The previous big opposition rally a day before Putin's inauguration in May ended in fierce clashes between police and protesters. The raids of the opposition leaders homes and their questioning were connected to the May 6 protest.