A statement issued on Friday said Bozidar Kuvelja, 40, first took part in the killing of the prisoners in a warehouse near the eastern town of Srebrenica before executing one by one about 100 men who had survived the massacre.The killing of over 8,000 Srebrenica men and boys after Serbs overran the town of Srebrenica is known as the worst massacre in Europe since the Nazi era and was declared genocide by the World Court.Several Bosnian Serbs have been tried or are still on trial for the massacre, including former Bosnian Serb leader Radovan Karadzic.Kuvelja was arrested in January.