Aiden Aslin, 28, and Shaun Pinner, 48, were both captured within days of each other while fighting alongside Ukrainian forces in the besieged city of Mariupol last month...
Both men were told they were charged with crimes against civilians.
Prosecutor Andrei Spivak said: “They are charged with a number of crimes against civilians of the Donetsk People’s Republic.
“The maximum punishment for these crimes is the death penalty.”
Aslin was heard saying he understood the accusations against him but did not agree that he had murdered civilians while fighting for the Ukrainians in Mariupol.