Events have taken place across the world to mark Holocaust Memorial Day.
It is 68 years since the Auschwitz-Birkenau concentration camp in Poland was liberated by Soviet forces.
The head of the Russian parliament opened a new exhibition on the Soviet Union's history at the camp.
Meanwhile, Minister for Justice Alan Shatter gave the keynote address at a commemoration at the Mansion House in Dublin.
Elsewhere, Holocaust survivors gathered in London for a candle-lit concert on the Millennium Bridge.
UN Secretary General Ban Ki-moon paid tribute to those who helped Jews during the Holocaust.
He said: "Let us be inspired by those who had the courage to care. The ordinary people who took extraordinary steps to defend human dignity.
"Some were able to avoid the slaughter. They escaped because of pure brave souls risked their lives and their families to rescue Jews and other victims of persecution from almost a certain death.
"Some sheltered the intended victims in their homes. Others helped families to obtain safe passage.
"Some of the accounts of the rescuers have achieved iconic prominence, but many are known only to those whose lives were saved."