The organisation called today for a retrial, and for a new examination of the evidence.

'The presumption of innocence of each of the accused was not respected,' Amnesty International said. The judge is reported to have told the defendants that 'it is impossible to determine your individual guilt, but that is not necessary'.

The 143 men, one of whom was a minor at the time of his arrest, were convicted of being members of the Kosovo Liberation Army (KLA), terrorism and attacking Serbian police.

Little attempt was made during the trial to establish individual guilt on the part of the accused. The key prosecution evidence, a forensic report whose scientific reliability is in question, simply lists the names of 155 men without detailing findings relating to any individual.

The accuracy of the 'paraffin glove' test for gunpowder, intended to show whether the subject has handled arms, has been widely challenged by forensic experts, and is known to produce a 'positive' reading in circumstances where materials other than gunpowder have been handled.

At the trial itself expert witnesses confirmed that the test is not wholly reliable and that the tests had been carried out in a 'shortened procedure'. Doubts were also raised about the exact tests used and the qualifications of those who had carried them out.

Despite all these concerns the court accepted the results as evidence. The judge is reported to have admitted that there may have been shortcomings in the tests, but decided to accept them nonetheless, since they were 'conducted in wartime conditions'.

Although the indictment listed three separate attacks on police in the Kosovo town of Djakovica (Gjakova) on 10 April, 7 and 9 May 1999, little attempt was made at the trial to connect the accused with all or any one of the attacks. Amnesty International is concerned that the right of the accused to call witnesses in their defence may have been violated by the court, which refused defence requests to introduce witness evidence from members of the Yugoslav army who had been present in Djakovica. Those who spoke in their own defence at the Nis trial denied being members of the KLA, and pointed out that during the NATO bombing a heavy police and army presence meant that they had little chance to move freely.

Background The men were among thousands arrested in Kosovo by Serbian police during the attacks by the North Atlantic Treaty Organization (NATO) on the Federal Republic of Yugoslavia. More than 2,000 Kosovo Albanians were moved to prisons in Serbia at the end of the NATO attacks as the Serbian police and the army withdrew. One thousand or more remain in prison, some still awaiting trial. Between 2,000 and 3,000 Kosovo Albanians remain missing; many have 'disappeared' at the hands of the Serbian police or paramilitary units.