UN war crimes judges have upheld a genocide conviction and life sentence against former Bosnian Serb military leader Ratko Mladic, rejecting all grounds of his appeal against a lower tribunal’s verdict.

Mladic, 78, led Bosnian Serb forces during Bosnia’s 1992-95 war.

Known as “the butcher of Bosnia”, he was convicted in 2017 on charges of genocide, crimes against humanity and war crimes.

They included terrorising the civilian population of the Bosnian capital Sarajevo during a 43-month siege, and the killing of more than 8000 Muslim men and boys in the eastern Bosnian town of Srebrenica in 1995.

He had been convicted by trial and ordered to serve life in prison but appealed against both the verdict and sentence.

The appeals chamber “dismisses Mladic appeal in its entirety …, dismisses the prosecution’s appeal in its entirety …, affirms the sentence of life imprisonment imposed on Mladic by the trial chamber,” said a written summary of the appeals judgment.

The verdict caps 25 years of trials at the ad hoc International Criminal Tribunal for the Former Yugoslavia, which convicted 90 people.

The ICTY is one of the predecessors of the International Criminal Court, the world’s first permanent war crimes court, also seated in The Hague.

-with AAP