Bosnia's Muslims will mark the anniversary of  the Srebrenica massacre on Saturday with their relations with Serbs at their worst in the 14 years since the slaughter.

The massacre of some 8,000 Muslim men and boys by Serb forces on July 11, 1995 – Europe’s worst atrocity since World War II -  is to be commemorated across Europe for the first time  Bosnia,  which remains sharply divided along ethnic lines.

The European Parliament in January proclaimed the date a day of commemoration of the Srebrenica genocide, calling on countries across the  continent to support the move.

While they admitted in 2004 that their forces killed 8,000 Srebrenica  Muslims, Bosnian Serb authorities condemned the resolution, in what’s seen as a reflection of the revival of nationalist rhetoric that triggered the country's 1992-1999 war.

In another act of defiance on Wednesday, Serb deputies in the Bosnian  parliament blocked an initiative to declare July 11 the Srebrenica genocide remembrance day in the former Yugoslav republic.

"Bosnia is facing the worst political crisis since the war," political analyst Srecko Latal told AFP.

"One of the rare encouraging things is that political tensions have not reflected on the relationships between ordinary people," he added, warning that this "might be changing."

Bosnia's inter-ethnic war cost 100,000 lives and left the country split into two highly autonomous entities -- the Muslim-Croat Federation and the  Serbs' Republika Srpska.

The eastern town of Srebrenica remains in the Serb-run half - a factor which  has added to tensions highlighted this month by the arrest of a massacre  survivor while entering Republika Srpska from Croatia.

The detention of Midhat Salihovic was condemned by groups representing survivors, which warned they would cancel Saturday's ceremony in protest.

Salihovic, who was to attend the burial of his father and brother both killed in Srebrenica, was released after questioning.

His arrest was "clearly politically motivated," said Mirsad Tokaca of the non-governmental Centre for the Investigation of War Crimes, adding that local leaders "politicise every issue and manipulate victims."

"We are fortunate to have not had some real incidents" because such abuse of Srebrenica survivors could cause them to react like a "bull to a red rag,"  said Tokaca.

Experts and analysts warn that events surrounding the massacre anniversary indicate deeper problems in post-war Bosnia.

Political tensions had been rising in the country since its 2006 elections, with Serbs threatening to secede and some Muslim leaders calling for the abolition of Republika Srpska.

Tens of thousands of Muslims are expected gather in Srebrenica on Saturday  to attend the memorial and burial ceremony for more than 500 newly identified victims.

Most of these remains were found in secondary graves, where they had been moved from initial burial sites in an attempt by Serbs to cover up war crimes.

So far some 3,200 victims have been buried at a memorial just outside the ill-fated town. Thousands are yet to be exhumed and identified in the area  where some 70 mass graves have been uncovered.

The massacre has been termed genocide by both the International Court of  Justice, which handles disputes between nations, and the International Criminal tribunal for the former Yugoslavia (ICTY).

Bosnian Serb wartime leader Radovan Karadzic, suspected of being behind the massacre, was detained last year and is awaiting trial before  the ICTY. His army chief and co-accused Ratko Mladic is still on the run.