Voters in Russia go to the polls Sunday in a parliamentary election that follows a campaign whose fairness is being called into question.

Russian police have broken up an opposition march in Moscow, and detained protest leader, former chess champion Garry Kasparov.

The Russian opposition says federal authorities appear to be behind attempts to discourage fair participation in their country's upcoming parliamentary and presidential-election campaigns.

Russian opposition politician Garry Kasparov says emerging divisions in the Other Russia movement are natural as it moves from staging street protests to preparing for the upcoming election season.

The opposition group Other Russia has begun its latest demonstration in Moscow. Opposition leaders Garry Kasparov and Eduard Limonov are among the estimated 1,000 participants, RFE/RL's Russian Service reported.

The opposition group Other Russia is due to hold a March of Dissent demonstration in St. Petersburg on June 9 to coincide with an international economic forum in the city.

Russia's second city of St. Petersburg is set to host a round of summits and an opposition demonstration this weekend. Thousands of international investors are due to descend on St. Petersburg for an economic forum in which President Vladimir Putin will try to soothe fears about Russia's political and economic direction.

Garry Kasparov, Russian opposition leader, said Monday that he will not give up his protest marches against Kremlin, in spite of many of them were violently dispersed by police or subjected to pressure and Kasparov was even blocked from taking part in march last week.

Russian opposition leader Garry Kasparov has compared the government of President Vladimir Putin to the dictatorships in Belarus and Zimbabwe. Kasparov said that while Russia might be closer to the European Union than to Africa, politically it resembles the dictatorship of Zimbabwe more than the democracies of Germany or France.

More than 100 demonstrators have rallied in the southern Russian city of Chelyabinsk to protest what they call President Vladimir Putin's authoritarian policies. One of the organizers of the March of Dissent, Oleg Stifonov, told RFE/RL that the rally proceeded peacefully.

Russian authorities' brutal crackdown on the March of Dissent rallies in Moscow and St. Petersburg earlier this month was just one element in a broader campaign of intimidation against Russia's political opposition and few remaining alternative mass media organizations.

Investigators from Russia's Federal Security Service (FSB) questioned opposition leader Garry Kasparov for four hours today. The questioning came less than a week after Kasparov was detained and released during antigovernment protests in Moscow on April 14.