Slobodan Medic and Branislav Medic were sentenced to 20 years in prison, Pera Petrasevic to 13 years, and Aleksandar Medic to five years in prison. The fifth indictee, Aleksandar Vukov, was acquitted because it was not proven that he had committed the crimes he was charged with.
The tribunal concluded that in 1995 the Scorpions paramilitary unit was part of the Bosnian Serb army.
The indictment was issued on the basis of a video showing members of the Scorpions unit killing six civilians from Srebrenica, three of whom were underage.
The video footage, made by other members of the unit, was shown for the first time during the war crimes trial against Slobodan Milosevic before the International Criminal Tribunal for the former Yugoslavia (ICTY) in The Hague in 2005.
The sixth perpetrator, Slobodan Davidovic, who was also identified in the video recording, has been sentenced by a Croatian court to 15 years in prison for war crimes.
Addressing reporters upon the verdict's announcement, prosecutor Vladimir Vukcevic said he was satisfied with the fact that the trial before the first-instance court had been completed in one year's time.
Vukcevic said he would appeal against Vukov's acquittal and against the length of the five-year prison term given to Aleksandar Medic.