It was one of the single most bloody events of the war in Bosnia-Herzegovina, and one of the most mysterious.
The single shell blast in Sarajevo's Markale market on 5 February 1994 killed 68 people and wounded more than 100.
The Muslim-led government blamed the besieging Serb forces.
They, in turn, accused the government of shelling its own people, to win international sympathy.
The blast in the crowded market place killed 68 people
A report by United Nations peacekeepers at the time was inconclusive, although there have been persistent rumours that a secret UN report later pointed the finger of blame at the government.
A mortar shell landed in the crowded market place just after noon, scything down the mainly civilian shoppers and traders between the tightly packed stalls.
Rescue workers and UN personnel who rushed to help described a hellish scene spattered with blood and body parts.
What aroused suspicion in some quarters was that the market was surrounded by high buildings and would normally have been considered safe from all but the most precisely targeted shell.
Other reports noted that television crews were on the scene, filming within seconds of the blast.
Indeed foreign broadcasters at the time, including at the BBC in London, were surprised at the speed and shocking detail with which they received the raw television pictures from Sarajevo.
General Michael Rose, the British head of the Sarajevo-based United Nations Protection Force (Unprofor), said at the time that he could not be sure who was responsible.
But in his memoir, Fighting for Peace, General Rose relates how three days after the atrocity he told the Deputy Commander of the Bosnian government forces, General Divjak, that the mortar shell had indeed been fired from their own side, according to UN experts.
That proved to be a telling intervention from the British general. Within days the government and the Serbs had agreed to a ceasefire which resulted, under Nato pressure, in the removal of most of the Bosnian Serbs' heavy weapons from the Sarajevo area, and the first loosening of the nearly two-year siege.
Although the UN never publicly accused the Bosnian Government of shelling its own people, Unprofor did accuse government forces of firing to provoke the Serbs, and of using hospitals and public buildings as cover for such fire.
Under General Rose, Unprofor was firmly focused on preserving or extending ceasefires, and opposed to any escalation of the fighting which might drag Nato or the Western powers into conflict.
The Bosnian Government, on the other hand, was deeply frustrated by the arms embargo and Western diplomacy, which it felt tied its hands and those of its hard-pressed troops.
In such an atmosphere of mutual mistrust, the Markale massacre 10 years ago and a similar attack in August 1995 became the focuses of outrage, recrimination, and ultimately successful military action by Nato forces to lift the siege of Sarajevo and bring the two sides to the negotiating table.
What angered many Sarajevans was that even if their government had shelled its own civilians in order to drag the Western powers into war against the Serbs, it was the Serbs who were responsible for the protracted shelling of the city and for the deaths of at least 10,000 people, including almost 1,800 children.
Galic was jailed for 20 years for his role in the siege of Sarajevo
Perhaps the final verdict on the Markale incident lies with the War Crimes Tribunal in The Hague. Last month the court sentenced Bosnian Serb General Stanislav Galic to 20 years in prison for his part in the attacks on civilians, including the Markale massacre.
General Galic was in command of the 18,000-strong Bosnian Serb Army from September 1992 to August 1994.
However, there will almost certainly be those who continue to blame the Bosnian Government for the atrocity.
The Helsinki Committee for Human Rights in Serbia noted that while the verdict on Markale against General Galic was widely reported in the international media, it was ignored in Serbia itself.