With Putin Leading Surveys, Russians Vote for President

Members of the Russian Interior Ministry walk, with St. Basil's Cathedral seen in the background, on the presidential elections day in Moscow, March 4, 2012. (Reuters)

A Russian navy serviceman casts his ballot during the presidential elections in the Ukrainian Black Sea port of Sevastopol, March 4, 2012. (Reuters)

Members of a voluntary public order and security squad sit near ballot boxes during the presidential elections in Moscow, March 4, 2012. (Reuters)

Russians queue to register for voting at a polling station in Moscow, March 4, 2012. (Reuters)

Russian cosmonauts Anatoly Ivanishin (L), Oleg Kononenko (C) and Anton Shkaplerov onboard the International Space Station communicate their votes at mission control centre in Korolyov, outside Moscow, March 4, 2012. (Reuters)

Russian expatriates prepare to cast their votes in the presidential election, at the Russian Embassy in London, March 4, 2012. (Reuters)

A woman casts her ballot in a mobile ballot box outside her house in the village of Oktyabrskoye, about 440 km (273 miles) from Moscow, March 4, 2012. (Reuters)

A monk fills in his ballot paper before voting during the presidential elections at the Nilova Pustyn monastery near the town of Ostashkov, some 350 km west of Moscow, March 4, 2012. (Reuters)

Russians are choosing a president for the fifth time since the collapse of the Soviet Union, 20 years ago. Opinion polls indicate Vladimir Putin is considered the leading candidate for a job that could keep him in the Kremlin through 2018.