The European Court of Human Rights (ECHR) said on Thursday it had issued an order to Russia to ensure that the death penalty was not carried out against two Britons who were captured after fighting for Ukraine.
Earlier this month, a court in the self-proclaimed Donetsk People's Republic (DPR) in eastern Ukraine sentenced British citizens Aiden Aslin and Shaun Pinner to death, accusing them of "mercenary activities".
The ECHR said it had issued an order for interim measures, telling Russia it "should ensure that the death penalty imposed on the applicants was not carried out; ensure appropriate conditions of their detention; and provide them with any necessary medical assistance and medication".
The men's families deny that the two, who were contracted to the Ukrainian armed forces, were mercenaries.
Britain has so far declined publicly to raise the issue with authorities in the DPR, whose independence is recognised only by Russia, instead saying it hoped Kyiv could secure the men's release.