MOSCOW, Sept. 10 (Xinhua) -- Russians cast their ballot on Sunday to fill two vacant seats at the State Duma (lower house of the Russian parliament) and elect heads of 16 federal subjects and parliament members of six federal subjects.

According to the Russian Central Election Commission, about 5,800 elections at various levels were held in 82 federal subjects, attracting some 46 million people, or nearly half of Russia's total voters.

A total of 18 candidates are running for the two State Duma vacancies and 105 others are bidding for local government heads. At the same time, 230 local referendums were held.

Members of 42 political parties and six social organizations are seeking these positions. United Russia is the largest and ruling party of the country.

The massive elections on Sunday was widely seen as a prelude to the 2018 presidential election.