Israel's president told of his own family's suffering at the hands of the Nazis in World War II, speaking at the Wednesday opening of the annual memorial day for the 6 million Jews killed in the Holocaust and drawing parallels with modern-day Iran.
Shimon Peres and Prime Minister Benjamin Netanyahu both called on the world to "learn the lessons" of the Holocaust and stop Iran from acquiring atomic weapons.
"The Iranian regime is acting openly and decisively toward our destruction, and it is acting feverishly to develop a nuclear weapon to achieve this goal," Netanyahu said.
Peres, who was born in the Polish town of Vishneva in 1923 and migrated to pre-state Israel before the war erupted, learned later how Nazi troops beat members of his extended family and ordered them to march toward the town's synagogue.
"Someone yelled 'Jews, save yourselves!' The Germans shot those who tried to escape. The rest arrived at the synagogue that was made of wood. Its doors were locked. They were all burned alive," he said. "That was also the last day of Rabbi Zvi Meltzer, my grandfather, my mentor. He was burned with a prayer shawl on his head. That was the last Jewish day in Vishneva. Not a single living Jew remained."
Peres, 88, spoke at Yad Vashem, Israel's official Holocaust memorial, before hundreds of Holocaust survivors and their families, Israeli leaders, diplomats and others.
The Israeli flag flew at half staff and a military honor guard stood at one side of the podium as poems and psalms were read and the Jewish prayer for the dead was recited.
Peres, a Nobel Peace Prize laureate, linked the Nazi genocide to Iran's suspected drive to acquire nuclear bombs and its leaders' repeated references to the destruction of Israel.
He said humanity "must learn the lessons of the Holocaust and face existential threats before it is too late."
"Iran is at the center of this threat. It is the center of terror. It poses a threat to world peace," he said.
Netanyahu also warned of the danger posed by Iran.
"Those who dismiss the Iranian threat as a whim or an exaggeration haven't learned a thing from the Holocaust," he said. "To be deterred from telling the truth _ that today, like then, there are those who want to destroy millions of Jews _ that is disrespectful of the Holocaust. That is an insult to its victims and that is ignoring its lessons."
The stated links between the Holocaust and Iran showed how more than six decades later, the mass murder of Jews during World War II is still a central part of Israel's psyche. The nation was created just three years after the end of the war, and hundreds of thousands of dazed survivors made their way to Israel.
Today, fewer than 200,000 elderly survivors remain in the country.
The annual memorial day is one of the most solemn on Israel's calendar. Restaurants, cafes and places of entertainment are shut down, and radio and TV programming are dedicated almost exclusively to documentaries about the Holocaust, interviews with survivors and somber music.
On Thursday morning, Israel is scheduled to come to a standstill as sirens wail for two minutes. Pedestrians typically stop in their tracks, cars and buses halt on streets and highways and drivers and passengers stand on the roads with their heads bowed.
Further ceremonies include the public reading of names of Holocaust victims at sites around the country, including Israel's parliament.
Wednesday night's main ceremony at Yad Vashem included six survivors who lit six symbolic torches to commemorate the 6 million dead. A video segment on each one's personal story was presented.
Hours before the opening ceremony, an annual report by Tel Aviv University on worldwide anti-Semitism said the number of attacks declined in 2011, but they were generally more violent than in previous years.
Moshe Kantor, president of the European Jewish Congress, said his organization expects anti-Semitic attacks to rise if European economies sink into further crisis, if Israel attacks Iran or if violence erupts between Israel and the Palestinians.
He cited the deadly attack on a Jewish school in Toulouse last month in which a rabbi and three children were shot dead, apparently by an extremist Muslim gunman, as indicative of his fears.