This renewed call includes the arrest of the Bosnian Serb leader Radovan Karadzic and his supreme Commander Ratko Mladic, both charged with genocide and crimes against humanity committed during the Sarajevo siege. Both men, who stand charged by the Tribunal with superior responsibility for serious violations of international law, are accused of acting in concert with others some of whom are already in the custody of the Tribunal awaiting trial.

'Radovan Karadzic and Ratko Mladic must be immediately arrested in the interests of justice and of establishing the truth,' Amnesty International said. In addition the organisation believes this would ensure a more efficient use of the Tribunal's resources; trial proceedings for those accused of ordering and participating in the same crimes will not have to be repeated and fragmented.

'Justice for the victims appears remote as long as those suspected of having committed serious human rights violations against the Sarajevo population remain at large, be they commanders or common soldiers.'

So far only one person - Bosnian Serb Major General Stanislav Galic - is standing trial before the Tribunal for crimes against humanity and war crimes committed during the siege. A second suspect jointly indicted with him, Corps Commander Dragomir Milosevic, remains at large and is believed to be in the Republika Srpska. In addition, trial proceedings against two former Bosnian Serb political leaders, Biljana Plavsic and Momcilo Krajisnik - both indicted for genocide and crimes against humanity in Bosnia-Herzegovina, including Sarajevo - are due to open later this year.

Few proceedings for war crimes have taken place in the domestic courts. 'In order for justice for the victims to be achieved, the national authorities in Bosnia-Herzegovina must investigate and prosecute those suspected of having committed human rights violations during the war, regardless of their rank or ethnic origin,' Amnesty International said.

The organization recommended that the Bosnian authorities ensure that the local judiciary is empowered to carry out prosecutions impartially and professionally, in order for the domestic criminal justice systems to complement the work of the Tribunal -- whose work is limited by its ad hoc nature and mandate. Urgent reforms must be made, both in legislation and practice, to tackle the legacy of impunity for the crimes perpetrated during the war which continues to pervade Bosnian society, denying victims and their relatives the right to a just remedy and reparation.

April 6 marks the tenth anniversary of the beginning of the siege of Sarajevo, and the subsequent devastating armed conflict which saw more than three years of large-scale and systematic gross violations of human rights. An estimated 10,000 people lost their lives in the siege of Sarajevo, most of them unlawfully killed as a result of both deliberate and arbitrary shelling and sniping by Bosnian Serb armed forces which controlled parts of the suburbs and the mountains surrounding the city.