Ceremonies are being held around the world today to mark Holocaust Remembrance Day.
Pope Francis spoke off the cuff at the end of his weekly general audience, warning that warped ideologies can pave the way to another mass extermination.
This is the 76th anniversary of the liberation of the Auschwitz death camp in Poland, where Nazis killed more than one-million Jews and others.
German Chancellor Angela Merkel attended a ceremony in Berlin.