Ten Bosnian Serb war crimes convicts, including six who took part in the Srebrenica massacre, have been freed from jail because of procedural errors.
Relatives of Srebrenica victims called the decision to release the men "shameful".
The European Court of Human Rights ruled the men's legal rights had been violated, because they were tried under the wrong criminal code.
They will now be subject to a retrial, a Bosnian court ruled.
The men were serving jail terms of up to 33 years.
Six were convicted of genocide for their roles at Srebrenica, when 8,000 Bosniak men and boys were murdered by Bosnian Serb paramilitaries in 1995.
Munira Subasic, who lost 22 family members in the massacre, said: "I feel like a victim again. I don't know where the released criminals now are. They could be standing behind my back as we speak."
The release follows a ruling in July, in which two men convicted in Bosnia's courts complained that they had been tried under a more stringent criminal code (from 2003) than the one (from 1976) in force when the crimes were committed.
The European Court of Human Rights ruled in their favour.
That encouraged the 10 to complain on the same grounds to the Bosnian Constitutional Court, which overturned their verdicts.
Justice in doubt
Criminal law expert Goran Simic told the Associated Press Bosnia was paying the price for "setting an unheard-of and unacceptable legal precedent" by deciding to apply the law retroactively in the first place.
The case is the latest to cast doubt on attempts to attain justice for the severe crimes of the Balkans wars.
Bosnian courts and the international tribunal at The Hague have been steadily working through a list of suspects, jailing many of those deemed responsible for the worst incidents of genocide, mass murder and ethnic cleansing.
Two of those accused of masterminding the genocide by Bosnian Serb forces, Gen Ratko Mladic and Radovan Karadzic, are on trial at The Hague.
But this year Momcilo Perisic, a Yugoslav army commander, was acquitted on appeal after initially being sentenced to 27 years in prison, apparently because of a change in perception about whether those at the top of the command structure could be held responsible for crimes committed by their men.
Two highest-ranking Serbian state officials were also acquitted despite establishing and training the feared Serb paramilitary squads that terrorised non-Serbs in Bosnia and Croatia, and providing the weapons that were used to kill them.
- 19 June 2013
- 28 February 2013