Bosnian police control streets in the center of the eastern Bosnian town of Srebrenica | Elvis Barukcic/AFP via Getty Bosnian Serb police guard ballots in Srebrenica They entered the municipal building to prevent a recount of votes.

Tensions were high in the Bosnian town of Srebrenica on Wednesday after Serbian police entered a municipal building to "secure the election material" following regional voting on Sunday.

A Serbian candidate Mladen Grujičić was projected to win the mayor's post. Srebrenica is the town where Serbian paramilitaries killed thousands of Muslim men and boys in 1995, the worst massacre in Europe since World War II and declared genocide by the international court.

The Bosnian Central Election Commission said there were irregularities in Sunday's vote and ordered a recount in Srebrenica and four other cities. However, Bosnian Sreb police seized the ballots and refused to hand them over.

However, Bosnia's October 2 local elections have been overshadowed by a referendum in Republika Srpska that took place a week before. The referendum confirmed a controversial national holiday in the Serbian entity, and was widely seen as a rehearsal vote on the entity's independence expected in 2018.

Recent events have deepened ethnic divisions that stem from the 1991-1995 war in which hundreds of thousands were killed and millions were uprooted from their homes, unable to return to this day.

Bosniak politicians have repeatedly warned the Serbs not to entertain ideas of breaking away from Bosnia and Herzegovina and taking with them territory where "places of great suffering" are located, according to Bakir Izetbegović, the Bosniak member of the tripartite presidency of Bosnia and Herzegovina.