Death sentences have been handed down to two British men and a Moroccan national who were captured while fighting for the Ukrainian army.
The three men are accused of being mercenaries in a self-styled court in the self-proclaimed Donetsk People's Republic, which allies itself with Moscow.
A spokesman for the British Prime Minister urged pro-Russian forces to treat the Britons as prisoners of war under the Geneva Convention.
Outside the courtroom, Ukranian fighters are on the ropes in the eastern region, as both sides sustain heavy losses.
The city of Severodonetsk remains the epicentre of the war there - President Volodymyr Zelenskyy saying that battle will decide the fate of the entire Donbas region.
The BBC's Joe Inwood spoke to Susie Ferguson.
