More than 320,000 police officers and 11,500 servicemen are to maintain security during the State Duma polls, which began at 20:00 p.m. GMT in Russia.
As of 3:00 Moscow time [23:00 GMT Saturday] the vote is underway in four Russian time zones, which cover a vast part of Siberia and all Far East.
"All polling stations (94,487 in total) will be patrolled by police officers tasked not only with maintaining security, but also with preventing violations of the electoral law, including illegal campaigning and bribery of voters," an interior ministry spokesman quoted First Deputy Interior Minister Alexander Gorovoy as saying.
A total of 51,500 of police officers will be on duty in Moscow, where over 3,300 polling stations will open at 4:00 a.m. GMT. Russian President Dmitry Medvedev and Prime Minister Vladimir Putin will cast their ballots in the Russian capital.
All polling stations were examined by sniff dogs trained to detect explosives.
After the voting the police will provide safe transportation of ballots and voting results.
The Russian emergencies ministry said it will deploy 686,700 people and almost 140 vehicles and other equipment to maintain security at polling stations, crowded areas, including transport and shopping malls, and at potentially dangerous industry objects.
Volatile Russian Caucasus regions took additional security measures ahead of the vote. Polling stations in Ingushetia, Dagestan, North Ossetia and Southern Russia's Stavropol Territory have been equipped with metal detectors.
Ingushetia, which has seen frequent militant attacks on security forces, police and civilians, closed all markets from Saturday afternoon until Monday. All schools in the region will also remain closed on Saturday and Monday.
The Russian Interior Ministry has opened 369 polling stations abroad, in which about 1.8 million Russian passport holders are to take part. The first Russians overseas to vote in the December 4 parliamentary elections were about 3,000 people living in New Zealand, where polling stations opened at 23:00 Moscow time on December 3. Russians living in San Francisco will be the last to vote as elections in their city will begin on December 5, Monday, Moscow time.
More than 16,000 Russian passport holders, many of them space industry employees, will be able to cast their ballot in the Kazakh city of Baikonur near the eponymous space center. Baikonur voters will test an electronic vote system, in which a voter chooses a party directly on the touch screen, after receiving a bar code card from the election commission.
Russian cosmonauts Anton Shkaplerov and Anatoly Ivanishin, members of the International Space Station (ISS) crew, will also take part in the vote. During a private communications session, they will tell their choice to a special trustee, who will then put the ballots into a box in the Mission Control Center.
At 00:00 a.m. Moscow time (20:00 GMT Saturday) polling stations opened in the Kamchatka Peninsula, which along with the Chukotka Autonomous Area and the Kolyma Region make up Russia's easternmost time zone.
An hour later, at 1.00 a.m. Moscow time (21:00 GMT) polling stations opened in the Far Eastern Primorye Territory and its capital Vladivostok, as well as in Khabarovsk Territory, Russia's largest island of Sakhalin and the Kuril Islands.
As of 2:00 Moscow time (22:00 GMT), the polls also began in the Amur Region, the Republic of Sakha (Yakutia) and the Transbaikal region.
At 3:00 Moscow time [23:00 GMT] Siberia's Irkutsk Region and the Republic of Buryatia joined in the vote.
