The so-called "death sentences" against three foreign members of Ukrainian forces by separatists' "courts" are blatant violations of international law, Amnesty International, the world's leading human rights organization, said on its website on June 9.
"This is a blatant violation of international humanitarian law on so many counts," said Denis Krivosheev, Amnesty International's Deputy Director for Eastern Europe and Central Asia.
He reiterated that the three were members of the Ukrainian regular forces and under the Geneva Conventions, as prisoners of war, they are protected from prosecution for taking part in hostilities.
"The only exception is prosecution for alleged war crimes, in which case there must be sufficient admissible evidence, and fair trial standards must be ensured," Krivosheev said.
"Not only this is not the case in this scenario – they were not tried by an independent, impartial regularly constituted court, but by Russian proxies. The so-called 'charges' against them would not constitute war crimes. And most outrageously of all, the taking of their lives as result of the grossly unfair proceedings would constitute arbitrary deprivation of life."
Amnesty International believes that "willfully depriving a prisoner of war or other protected person of the right to a fair and regular trial constitutes a war crime."
"Russia, as the occupying power, bears responsibility for the treatment of all prisoners of war and others deprived of their liberty," reads the report.
"They must ensure this so-called 'sentence' is immediately quashed, and that these men are treated in full compliance with international humanitarian law."
Two UK nationals, Aiden Aslin and Shaun Pinner, along with Moroccan citizen Saadun Brahim, were sentenced to death on June 9 by a sham court in the Russian-controlled part of Ukraine's Donetsk Oblast.
Both UK and Ukraine's foreign ministries have condemned the court's decision, saying that two Britons are PoWs and no sentences of the illegitimate court have any legal force.
Ukraine's General Staff said that any foreign nationals who defend Ukraine have signed contracts with the Ukrainian armed forces voluntarily and in accordance with Ukrainian law.
According to the Geneva conventions, all Ukrainian military service members, legally combatants, should be treated as PoWs by the enemy if they are captured.