Wartime Bosnian Serb leader Radovan Karadzic on Friday lodged an appeal against his 40-year jail sentence for genocide, accusing UN judges of "subjecting him to a political trial".
Warcrimes prosecutors also appealed the sentence, asking the court to put Karadzic behind bars for life.
Karadzic, who appealed on 50 grounds before the UN's Yugoslav war crimes court, "was subjected to a political trial that was simply designed to confirm the demonisation of him and the Bosnian Serb people," his lawyer Peter Robinson said in a statement.
Once the most powerful Bosnian Serb leader, Karadzic, 71, was sentenced in March for genocide over the 1995 Srebrenica massacre and nine other charges stemming from Bosnia's bloody three-year war.
More than 100,000 people died and more than 2.2 million others were left homeless in the conflict that followed the break-up of the former Yugoslavia after the fall of communism in the early 1990s.
Judges at the International Criminal Tribunal for the former Yugoslavia (ICTY) ruled that Karadzic, the most high-profile figure convicted over the wars that tore the Balkans apart, bore criminal responsibility for murder and persecution during the Bosnian conflict.
- 'Cryptic conversation' -
Almost 8,000 Muslim men and boys were butchered and their bodies dumped in mass graves in Srebrenica in eastern Bosnia in mid-July 1995, when Bosnian Serb forces brushed aside lightly armed UN Dutch peacekeepers protecting a UN safe area.
The massacre was the largest bloodshed on European soil since World War II.
A long-time fugitive from justice until his arrest on a Belgrade bus in 2008, Karadzic was also found guilty of being behind the harrowing 44-month siege of Sarajevo in which 10,000 civilians died in a relentless campaign of sniping and shelling.
He was however found not guilty on a genocide charge relating to killings in seven Bosnian towns and villages two decades ago, with judges saying they did not have enough evidence "beyond reasonable doubt" to convict Karadzic.
Robinson said Karadzic did not receive a fair trial and that UN judges "presumed him guilty and then constructed a judgement to justify its presumption".
Nowhere was this more apparent "than when the trial chamber found him guilty of genocide by inferring that he shared the intent to kill prisoners from Srebrenica based on (the court's) interpretation of a cryptic intercepted conversation," Robinson said.
Karadzic himself called the verdict "injust".
"Having spent eight years in a UN prison and gone through a five-year trial... Karadzic is convinced that international justice is a failed project," Robinson added.
- Trial 'errors' -
ICTY chief prosecutor Serge Brammertz also filed four grounds of appeal including that judges "erred in law and fact" when they failed to find that Karadzic had genocidal intent in the Bosnian municipalities.
"The prosecution requests that the appeals chamber correct the trial chamber's errors and increase Karadzic's sentence to life imprisonment," Brammertz said in a document filed before the court.
The one-time psychiatrist is the highest-ranking official to face judgement at the ICTY, set up in 1993 to prosecute those who committed crimes during the Balkans wars.
Former Serbian strongman Slobodan Milosevic was also on trial, but died in his prison cell in 2006 before the proceedings could be concluded.
Also still on trial is Karadzic's military alter ego Ratko Mladic, who was in charge of the Bosnian Serb troops that overran Srebrenica.
Mladic faces similar charges to Karadzic.
During Karadzic's marathon trial, which ended in October 2014 after an exhausting 497 days in the courtroom, some 115,000 pages of documentary evidence were presented along with 586 witnesses, while court officials recorded some 47,500 pages of transcripts.
Earlier this year Karadzic revealed that on the day of the judgement he was so convinced he would walk free that he had already packed his bags.