Bosnians were voting on Saturday in their third post-war local elections, which are expected to confirm the dominance of the ruling Croat, Muslim and Serb nationalists.
Turnout for the election was expected to be low due to widespread apathy among Bosnians burdened by economic hardship. Analysts said this could benefit the nationalist parties, which have a stable voter base in the former Yugoslav republic.
Three powerful nationalist parties which led Bosnia's 1992-95 war of independence from communist Yugoslavia - the Muslim Party of Democratic Action (SDA), the Croat Democratic Union (HDZ) and the Serb Democratic Party (SDS) - were tipped to win in a majority of municipalities dominated by their respective ethnic groups.
Some 2.3 million Bosnians were eligible to vote on Saturday to elect councillors in 142 municipalities and 140 mayors. The latter will, for the first time, be elected directly in one round.
Polling stations opened at 7:00 am (0500 GMT) and were due to close at 7:00 pm (1700 GMT). First partial results were expected around midnight (2200 GMT).
The electoral commission said 20 percent of voters had cast their ballots by noon (1000) GMT, a slightly lower figure than in the general election two years ago, when total turnout was 55 percent.
The 2002 general election was the first nation-wide poll to have been organised by the Bosnian authorities since the war ended. Saturday's ballots were the first local elections they have organised since the war.