Bosnians are set to go to the polls to choose a tripartite presidency and a parliament, but the general election is likely to further entrench ethnic divisions that have brought virtual political stalemate to the Balkan state.
Campaigning for Sunday's polls has been dominated by nationalist rhetoric and voting is largely expected to fall along ethnic lines, 15 years after a devastating conflict sparked by the break-up of Yugoslavia.
Tanja Topic, a political analyst, compared the campaign to 1990, when communist Yugoslavia had just collapsed and Bosnia was split it should become part of a greater Serbia or be an independent multi-ethnic country.
"So for exactly 20 years we have been spinning around in the same political pattern,'' Topic told The Associated Press.
The country's Serbian parties have focused on their demand for secession for the currently largely self-ruling Republika Srpska, while Croats have called for their own autonomous region.
Milorad Dodik, the Republika Srpska prime minister, has used the International Court of Justice ruled in July that Kosovo's declaration of independence from Serbia was legal as the basis for his demand for an independence state.
"Only the Serb Republic is self-sustaining, Bosnia-Herzegovina is not," he told a pre-election rally.
Dodik has also entered into a "strategic partnership" with Dragan Covic, the Bosnian Croat nationalist leader, to support each others' calls for greater independence.
The majority Bosniak Muslims have said they will fight for a united Bosnia-Herzegovina and are seeking a stronger central government, a key condition for European Union membership.
"We are determined to stop all attacks on our country and our people," Sulejman Tihic, the head of the Muslim Party of Democratic Action (SDA). "Any attempts at secession or the establishment of a third entity will not go through."
Valentin Inzko, the international envoy who oversees the country's peace process, has called on citizens to go out and vote.
"Please, get out and vote on Sunday," the Austrian diplomat told Bosnians. "This is your country, and it is your democratic responsibility to decide about its future."
More than 5,200 polling stations open at 7am (05:00 GMT) and close 12 hours later.
About three million voters will choose from a total 8,000 candidates for the shared presidency, and for the central and several regional legislatures.
The latest opinion polls suggest that Dodik's Alliance of Independent Social Democrats (SNSD) is set to remain the strongest party in the Serb Republic and probably in the country.
The multi-ethnic Social Democratic Party (SDP), headed by computer science professor Zlatko Lagumdzija and the country's largest opposition party, is tipped to become the strongest party in the Muslim-Croat federation, followed by the SDA.
Dodik has dismissed the possibility of any coalition with Lagumdzija at the state level, which could drag out the formation of a new central government for months.
The first official results for the presidency were expected by midnight, while preliminary results in the other races could come out by Monday morning.
More than 1,200 observers, including 485 international observers, have been registered to monitor the vote.
Source: Al Jazeera and agencies