OSWIECIM, Poland (Reuters) - Israel's leaders, with Iran on their minds, vowed never again to allow the "hand of evil" to kill Jews as the world marked International Holocaust Memorial Day on Wednesday.
Speaking at the former Nazi death camp of Auschwitz, liberated by Soviet Red Army troops 65 years ago, Prime Minister Benjamin Netanyahu said a strong Israeli state was the only guarantee for the security of his people.
In Berlin, Israeli President Shimon Peres told the German parliament Iran posed a threat to the whole world and lashed out at its president, Mahmoud Ahmadinejad, who denies the Holocaust and has called for the destruction of the Jewish state.
"From this site, I vow as the leader of the Jewish state that we will never again allow the hand of evil to destroy the life of our people and the life of our state. Never again," Netanyahu said at the Auschwitz ceremony.
"We will not allow the deniers of the Holocaust... to erase or distort the memory (of what happened)," he said, in a clear reference to Ahmadinejad's denial of the Nazis' genocide.
Poland's president and prime minister, the education ministers from nearly 30 nations, including Russia, and about 150 camp survivors attended the commemoration. In subzero temperatures, young Israelis placed candles on top of the crematoria nearby where the Nazis' victims were gassed.
Up to 1.5 million people, mostly Jews, perished at Auschwitz, located near the village of Oswiecim in southern Poland, before Soviet troops liberated it on January 27, 1945.
Auschwitz-Birkenau was the largest and most notorious of the Nazi death camps. Others operated by the Germans on occupied Polish territory included Majdanek, Sobibor and Treblinka.
Like Netanyahu, Peres stressed the need for vigilance.
"Never again ignore blood-thirsty dictators, hiding behind demagogical masks, who utter murderous slogans," he told the German lawmakers in a speech delivered in Hebrew.
"The threats to annihilate a people and a nation are voiced in the shadow of weapons of mass destruction, which are held by irresponsible hands, by irrational thinking and in an untruthful language," said Peres.
Western nations and Israel suspect Iran of trying to build nuclear weapons, a charge Tehran denies.
Peres, 86, recalled how his grandfather was burned to death in a Belarus synagogue that the Nazis locked from the outside.
Russian President Dmitry Medvedev, who declined a Polish invitation to attend Wednesday's ceremony, warned in a message read out at the Auschwitz commemoration by Russia's education minister Alexei Fursenko of attempts to rewrite history by downplaying the role of the Red Army.
Russians are immensely proud of their country's role in defeating Hitler's Germany at huge human cost. The Auschwitz ceremony was widely shown in Russian state media and Russian Jewish groups organized memorial services across the country.
The theme of the Auschwitz commemoration was the education of young people about the Holocaust.
"This place determined who I am today, aged nearly 90. I still have one mission -- to pass on to the next generation knowledge of what happened here," August Kowalczyk, one of very few of the camp prisoners to escape, told reporters at the site.
"The need for teaching about Auschwitz is greater than ever before," Wladyslaw Bartoszewski, 87, a Catholic survivor of Auschwitz and now the Polish government's special envoy for relations with Germany, said at the ceremony.
Poland was home to Europe's largest Jewish community before World War Two. The vast majority perished in the Nazi camps.
Jewish groups have voiced concern about what they see as a rise in anti-Semitism and xenophobia in some European countries and have called for more education about the Holocaust.
Earlier this week, they angrily criticized a Polish Catholic bishop after he was quoted as saying Jews had expropriated the Holocaust as a propaganda weapon. Roma, homosexuals and other groups were also systematically murdered there by the Nazis.
Speaking to the Italian parliament in Rome on Wednesday, Nobel Peace Prize winner and Holocaust survivor Elie Wiesel attacked wartime Pope Pius XII for his "silence" during the Nazis' mass killings of Jews.
German-born Pope Benedict has annoyed Jews by defending the actions of his wartime predecessor.
Additional reporting by Philip Pullella in Rome and Erik Kirschbaum in Berlin and Moscow bureau; Writing by Gareth Jones; Editing by Charles Dick