Ukraine is investigating an allegation that Russia shot an unarmed prisoner of war.
The mercenary group is offering contracts with bonuses for performance value.
The bodies of British aid workers were returned to Ukraine before making their way back to the UK.
Hamas released a video that depicted Mengistu, an Israeli civilian, speaking a few short sentences on Monday.
Russia has released US Navy veteran Dudley, who had been backpacking near the Russian border in Poland.