Ukrainian President Volodymyr Zelensky lays a candle on Holocaust Remembrance Day in front of the "Menorah" monument at the Babyn Yar site - a ravine in Kyiv, where Nazis executed more than 30,000 Jews in 1941. Between 1941 and 1944, about 1.5 million Ukrainian Jews were massacred, often by shooting, by Nazis who, on the move, were sometimes assisted by local collaborators.