Bosnia is marking 20 years since the start of a war that has left the country's Muslims, Serbs and Croats deeply divided as some warn it could become Europe's failed state.

6 Apr 2012 - 4:12 PM  UPDATED 26 Aug 2013 - 10:48 AM

Bosnia is one of the poorest countries in Europe and has 40 percent unemployment. It has been unable to push through EU-sought reforms as politics are completely divided along ethnic lines.

"The traces of war are deeply embedded in the relations between people and communities. Bosnia-Hercegovina is a prisoner of nationalist forces and is sliding backwards," Raif Dizdarevic, a former Yugoslav president told AFP.

Twenty years ago Bosnia plunged into war as the former communist Yugoslavia broke apart along ethnic lines.

Bosnia's Muslims and Croats voted to break free from the former federation in a referendum, which was boycotted by the Serbs who wanted to remain in Belgrade-dominated rump Yugoslavia.

After weeks of rising ethnic tensions and incidents on April 5 and 6, 1992 more than 50,000 people gathered in front of the country's parliament to demand peace.

Bosnian Serb snipers opened fire on protesters killing two women, the first civilian victims in the Bosnian conflict.

"I thought we could keep the peace but I was very naive because the war was already prepared, all the logistics were in place," law professor Zdravko Grebo who was at the protest, told AFP.

War officially broke out on April 6, 1992, the same day the European Community (now the European Union) recognised Bosnia as an independent country.

In the following three and a half years the country was torn apart, divided along ethnic lines despite international sanctions imposed on the Bosnian Serbs and neighbouring Serbia which supported them.

Some 100,000 people were killed and half the population of 4.4 million fled their homes. Sarajevo suffered the longest city siege in modern history and on Friday the town will host a concert for thousands of empty chairs to commemorate the over 10,000 people killed by Bosnian Serb shells or snipers.

The better trained and armed Bosnian Serbs embarked on a campaign of ethnic cleansing driving out Muslims and Croats from what they considered Serb territory leaving a trail of massacres and rapes.

Their political and military leaders Radovan Karadzic and Ratko Mladic are both facing trial for genocide before the UN war crimes court in The Hague.

It was the 1995 massacre of 8,000 Muslims after the fall of the UN "safe area" Srebrenica by Mladic-led troops that finally led to NATO intervention which forced Bosnian Serbs into retreat. The massacre is the only episode of the Bosnian war to have been ruled a genocide by a UN war crimes tribunal and the UN's top court, the International Court of Justice.

In November 1995, the Western-imposed Dayton peace agreement was signed by the presidents of Bosnia, Croatia and Serbia, creating a two-entity state -- Muslim-Croat Federation and Bosnian Serbs' Republika Srpska.

While the deal brought peace it also cemented the ethnic divisions that still haunt the country today. Bosnia's two semi-autonomous entities have their own political institutions, loosely connected through a almost powerless central government.

Relations with neighbouring countries like Serbia are slowly improving. The Serbian parliament in 2010 apologised for Belgrade's role in the Srebrenica massacre. Later that same year Serbian president Boris Tadic attended the Srebrenica commemoration for the second time but many victims protested his presence.

The 2010 elections triggered the longest political crisis since the war, when politicians bickered for 16 months before forming a central government prompting the International Crisis Group to warn that Bosnia could end up a "failed state" as divisions between Muslims, Croats and Serbs become more entrenched.

The political squabbles mean Bosnia has been trailing behind other Western Balkan EU hopefuls and has not even applied for candidate status.