Ukrainian President Petro Poroshenko (Front C) attends a ceremony commemorating the massacre of about 150,000 Nazi victims in Babi Yar near Kiev from 1941 to 1943, in Kiev, Ukraine, on Sept. 30, 2016. Babi Yar, a ravine in Kiev, was a site of a series of massacres carried out by the Nazis during their campaign against the former Soviet Union during WWII. (Xinhua/Sergy)