Holocaust survivors, politicians and religious leaders marked International Holocaust Remembrance Day Sunday with solemn prayers and warnings to never let such tragedies happen again.
Events took place at sites including Auschwitz-Birkenau, the former Nazi death camp in southern Poland liberated by Soviet forces on January 27, 1945.
At least 1.1 million people were murdered in Auschwitz, mostly Jews. In Warsaw, prayers were also held at a monument to the fighters of the Warsaw Ghetto Uprising of 1943.
Pope Benedict warned that humanity must always be on guard against a repeat of murderous racism.
U.S. President Barack Obama vowed to prevent genocide while honoring "the six million Jews and millions of other innocent victims whose lives were tragically taken during the Holocaust." He called Holocaust Remembrance Day a "time for action."
Not all words spoken by dignitaries struck the right tone.
Former Italian Prime Minister Silvio Berlusconi sparked outrage Sunday with remarks praising wartime dictator Benito Mussolini for "having done good" despite Fascist Italy's persecution of Jews and allowing thousands to be deported to Auschwitz.
Also Sunday, the Organization for Security and Cooperation in Europe urged renewed efforts to fight intolerance, stressing the importance of youth human rights education. The OSCE urged member states to develop educational programs to instill the memory of the holocaust in future generations to prevent another genocide.