The Hague (AFP) - Two former Serbian intelligence chiefs played a major role in running death squads that terrorised Bosnia and Croatia in the bloody 1990s Balkans wars, a UN court heard on Tuesday.
Jovica Stanisic, 66, and Franko Simatovic, 67, are back in court on four charges of crimes against humanity and a war crimes charge after their acquittal in 2013 was overturned.
"These accused made these crimes happen through their direction and unflagging support to the Serb forces who committed them," UN prosecutor Douglas Stringer told judges in The Hague.
Stringer said the accused "repeatedly deployed their... units in attack operations in Croatia and Bosnia where many crimes of persecution, murder and expulsion were committed."
"The evidence will show that this relentless pattern continued for over four years and that the accused supported and advanced it every step along the way," he said, as the two men listened attentively, with Stanisic occasionally shaking his head.
Stanisic and Simatovic's acquittal before the International Criminal Tribunal for the former Yugoslavia (ICTY) unleashed a storm of protest and was overturned in 2015 after prosecutors appealed.
The two men were ordered to return to the tribunal in The Hague to face a retrial on the same charges.
- Death squads -
Stanisic, the former head of Serbia's old state security service and a key figure in the regime of Slobodan Milosevic, and his deputy Simatovic now stand accused once again of organising, financing and supplying paramilitary groups.
These groups cut a swathe of terror and destruction across Croatia and Bosnia during the conflicts that erupted amid the collapse of Yugoslavia.
They included an elite unit dubbed the "Red Berets" and the feared paramilitary outfit run by Zeljko "Arkan" Raznatovic, called "Arkan's Tigers".
The death squads attacked towns and murdered Croats, Muslims and other non-Serbs to force them out of large areas, seeking to establish a Serb-run state, prosecutors alleged, seeking life sentences for both men in the original trial which opened in 2008.
UN prosecutors maintain that Stanisic and Simatovic were part of a joint criminal enterprise that included the late Serbian president Milosevic and Bosnian Serb leader Radovan Karadzic.
Stringer on Tuesday made a pointed reference to Milosevic -- who died in 2006 during his own genocide and warcrimes trial in the ICTY's custody.
"The substantial powers and authority wielded by Stanisic emanated not only from his position as head of the Serbian (security service) but also from the trust and confidence placed in him by Milosevic," the prosecutor said.
- 'Forcible, permanent removal' -
An estimated 100,000 people died in the Bosnian conflict, which saw some of the worst atrocities in Europe since World War II, and during which 2.2 million people were forced from their homes.
The indictment alleges the joint criminal enterprise between April 1991 and December 1995 aimed for the "forcible and permanent removal of the majority of non-Serbs from large areas in Croatia and Bosnia and Herzegovina".
But the ICTY's trial judges said in May 2013 that although the Serbian units carried out the killings, Stanisic and Simatovic could not be held criminally responsible as they did not give the units specific orders to commit the crimes.
The trial judges also said there was not enough evidence linking the men to a joint criminal enterprise.
In a rare turnabout however, that judgement was quashed on appeal by the prosecution in December 2015, when the appeals court found that the trial judges had "erred" on several points of law.
Stanisic and Simatovic are among the last top Balkans officials still being held in The Hague and are being retried by a different UN tribunal wrapping up outstanding cases.
Karadzic was last year sentenced to 40 years in jail on charges of genocide, war crimes and crimes against humanity -- notably for his role in the 1995 Srebrenica massacre in which almost 8,000 Muslim men and boys were slaughtered.
He has appealed, but no date has been set for a new hearing.
A verdict is also keenly awaited at the ICTY in the case of former Bosnian Serb army chief Ratko Mladic, dubbed the "Butcher of Bosnia".