Bulgarian train (Bosnian, Macedonian, Montenegrin and Serbian Cyrillic: бугарски воз, romanized: bugarski voz;[1][2][3] Croatian: bugarski vlak[4]), in Bulgaria known as Indian string (Bulgarian: индианска нишка, romanized: indianska nishka), is a method of vote-rigging with the goal of influencing the election process through the control of ballots.
The name of the method originates from its widespread use during the European Parliament election held in Bulgaria in June 2009, at which analysts' estimates indicate that 200,000-350,000 votes were sold or coerced.
[5][6] Bulgarian train is a method of vote-buying that includes a recurrent process of casting pre-filled ballots.
[12] Bulgarian train was reported in Teslić during the Bosnian general election in October 2014, when the voting process was interrupted until the suspicious person was cleared from the polling station.
[13] A variation of the Bulgarian train was reported in Hungary used by Fidesz primarily buying votes from the Roma community in the 2014 and 2018 elections.