Holocaust survivors, politicians, religious leaders and others worldwide are marking International Holocaust Remembrance Day with solemn prayers and the now oft-repeated warnings to never let such horrors happen again.

January 27, 1945 was the historical day when the Soviet troops liberated the German Nazi-run Auschwitz-Birkenau death camp in Poland, and it was designated Holocaust remembrance day by the United Nations in 2005.

This year's theme is "Rescue during the Holocaust: The Courage to Care," honoring people who risked their lives to save Jews and others from almost certain death under Nazi rule.

In a statement, UN Secretary-General Ban Ki-moon said the example of those who risked their lives to save Jews and others from mass extermination should inspire the people of today to take action for a better world.

European Parliament President Martin Schulz marked the event by inaugurating the Raoul Wallenberg room at the European Parliament building. Wallenberg was a Swedish diplomat who saved thousands of Jews from the death camps.

Ukrainian Foreign Minister Leonid Kozhara, who is chairperson-in-office of the Organization for Security and Cooperation in Europe  has called for "renewed efforts to fight intolerance, discrimination, and hate crimes."

In Moscow, Chief Rabbi of Russia Berel Lazar presided over a candle-lighting ceremony at the Jewish Museum and Tolerance Center.

"We should remember every victim," Lazar said. "We should remember everyone who had a miracle of freedom." He praised the Soviet Red Army and its allies "who paid in blood for bringing peace to Europe."

On Sunday, hundreds of Jewish tourists  visitng from abroad have also made their way to the Israeli holocaust museum Yad Vashem in Jerusalem, where an official memorial ceremony was held.

In addition to the memorial service, the museums launched a new exhibition of objects from the war called "Gathering of the Fragments," including 71,000 different items.

"Thousands of Israelis  and Jews from around the world have decided to part from personal items in their hearts, belonging to their family, and through them share the memories of their beloved ones who were murdered in the holocaust,"  saidAvner Shalev, Yad Vashem chairman.

Approximately 6 million European Jewish children, women, and men have perished in the Holocaust.