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Polls opened in the eastern parts of Russia Sunday in a presidential election likely to return Vladimir Putin to the Kremlin for a third term.

Ahead of the polls, the opposition held unprecedented protests across the country against him and his ruling United Russia Party.

Hundreds of thousands of Russians have taken to the streets across the country since Mr. Putin's United Russia Party won the parliamentary elections in December. Demonstrators claim the party won by ballot stuffing and vote rigging – charges the party denies.

The last independent public opinion poll ahead of the election says Mr. Putin is expected to avoid a runoff election with 62 to 66 percent of the vote in Sunday's vote.

Recent polls show that 80 percent of Russians believe Mr. Putin will return to the presidency, and 57 percent believe he is still the nation's leader, even though Dmitry Medvedev is officially president. Mr. Putin served two terms as Russia's president, from 2000 to 2008, before becoming prime minister.

Mr. Putin has four challengers, most of whom are familiar faces in Russian politics. Communist Party head Gennady Zyuganov is expected to place second in the vote, while nationalist Vladimir Zhirinovsky and billionaire Mikhail Prokhorov, a newcomer, are expected to battle for third place. Former Putin ally Sergei Mironov placed last in the 2004 presidential election and is expected to do so again.

Polls opened in Russia's Far East at 2000 UTC Saturday, and close in Kaliningrad, Russia's westernmost territory, 21 hours later .

Following allegations of fraud in December's parliamentary elections, Mr. Putin announced a $500 million program to install two web cameras at each of Russia's nearly 100,000 polling stations.