Voters across Russia were casting their ballots Sunday in the country's sixth parliamentary elections, as seven parties vied for representation in the 450-seat State Duma, or lower house.

People register to vote at a polling station in Moscow, Russia, Dec. 4, 2011. Voters across Russia started casting their ballots in the country's sixth parliamentary elections on Sunday, with seven political parties vying for slots in the 450-seat State Duma, the lower parliamentary chamber. (Xinhua/Jiang Kehong)

In a vast country split by nine time zones, polling was already in full swing in Siberia and the Far East when stations in the western regions, including the capital Moscow, opened at 400 GMT Sunday.

Voters in Kaliningrad, the westernmost exclave of Russia, located between Poland and Lithuania, were the last to start casting ballots at 0500 GMT and to conclude the voting in the country at 9:00 p.m. Moscow time (1700 GMT) on Sunday.

Among those using the more than 3,300 polling stations in Moscow were President Dmitry Medvedev and Prime Minister Vladimir Putin.

Medvedev and his wife, Svetlana, came to Moscow school, the No. 1118 polling station in the Dovzhenko Street to vote, while Putin cast his ballot at the No. 2079 polling station located in the Russian Academy of Science building, several kilometers from the Kremlin.

After voting, Putin said he wanted the United Russia party to achieve a good result at the elections and he expected more people would go to the polls.

As of 1:00 p.m. Moscow time (0900 GMT), 25.4 percent of the country's electorate had voted, according to deputy head of the Central Elections Commission (CEC) Leonid Ivlev.

The Interior Ministry said more than 320,000 police officers and 11,500 servicemen were deployed to maintain security during the polling.

"All polling stations in the country will be patrolled by police tasked not only with maintaining security, but also with preventing violations of the electoral law, including illegal campaigning and bribery of voters," a ministry spokesman told RIA Novosti news agency.

In the volatile North Caucasus regions, metal detectors were installed at polling stations before the vote.

Russian media said some 55 percent of the country's 110 million eligible voters were expected to cast ballots in some 94,000 domestic polling stations and about 370 overseas stations in more than 140 countries.

The first overseas polling stations to open were in New Zealand, where voting started at 1900 GMT Saturday and the last ones will be in San Francisco in the United States.

The seven political parties competing in the elections are the ruling United Russia party, the main opposition Communist Party, the Liberal Democratic Party of Russia, A Just Russia, the Yabloko (Apple), the Patriots of Russia and the Right Cause.

Some 3,000 candidates have been registered on the federal lists.

Under amendments to the country's electoral laws in late 2008, the new Duma will serve a five-year term instead of four.

VietNamNet/Xinhuanet