Ceremonies in Sarajevo are marking 20 years since the start of the war in Bosnia-Hercegovina, a conflict that saw the worst atrocities in Europe since World War II.
The conflict began in April 1992 as part of the break-up of Yugoslavia.
About 100,000 people were killed and nearly half the population forced from their homes in four years of fighting.
Red chairs have filled the street in Sarajevo where the conflict began - 11,541, one for each victim there.
People have been putting flowers on some of the chairs. A teddy bear, toys and schoolbooks were placed on the smaller ones that symbolise the hundreds of children killed during the four-year long siege by Serb forces.
Sarajevans were asked to stop what they were doing at 12:00 GMT for an hour to mark the start of the conflict.
Tearful memoriesThousands of people have been walking past the chairs, which stretch for 800m (half a mile) along the central street in Sarajevo named after the founder of Yugoslavia, Marshal Tito. Many were overcome with emotion.
"The amount of the chairs really hit me, especially the little ones," Ana Macanovic told Associated Press. She put white roses on seven chairs - each for a member of her family killed by mortar shells during the siege.
"It's as if the whole tragedy materialised, became visible," a tearful Asja Rasavac told AP. "One cannot even describe the feeling. It's not hatred. It's not anger. It's just endless sadness."
On a stage in front of the chairs, a choir and small classical orchestra performed songs, many composed during the siege.
"Everyone in Sarajevo has someone's chair, a mother, brother, friend or relative," Bosnian Foreign Minister Zlatko Lagumdzija told the BBC.
"This isn't about 20 years ago, this is about how to avoid something like this happening again," he said.
The Reuters news agency says the autonomous Serb area of the country is ignoring the anniversary of the start of the fighting.
For three years and eight months in the early 1990s, Sarajevo was a city under siege. The mainly Muslim population took cover, as Serb gunners barraged the city from the hills surrounding it.
The worst single atrocity during the war was at Srebrenica, in eastern Bosnia, in July 1995. Bosnian Serb forces, led by Gen Ratko Mladic, overran what should have been a UN safe haven. About 8,000 Muslim men and boys were taken away and killed.
As a result the UN changed the mandate for its mission and allowed force to be used.
But the war in Bosnia was a three-way mix, involving Serbs, Croats and Muslims.
The country is now run by a weak central government having little influence with each community living in separate regions, their children learning three different versions of history.
There are fears that despite the large amounts of aid money spent in Bosnia on integrating the country, the ethnic divisions will only get deeper.
The European Union's special representative to Bosnia, Peter Sorenson, says that during the war, trust and relations between people were simply destroyed. All of this, he says, can never be forgotten or "wiped away".
The BBC's Genc Lamani says that the aspirations for a multi-ethnic and multi-cultural Bosnia have not yet become a reality. Many people in Bosnia believe the war was too high a price to pay for such hopes, our correspondent says.