For what may be the last time, elderly Holocaust survivors returned to the infamous Auschwitz-Birkenau death camp 70 years after its liberation Tuesday, to urge the world never to forget one of history's worst atrocities.
Around 300 survivors, some wearing scarves in the blue-and-white stripes of their death camp uniforms, joined world leaders for an emotional memorial at the epicenter of the Nazi genocide of Jews.
The commemoration at the cold and austere camp, which was blanketed in snow, comes amid concern over a resurgence in anti-Semitism in France, Germany and other parts of Europe.
"We do not want our past to be our children's future," said survivor Roman Kent, 86, his voice breaking with emotion.
"Witnessing the atrocities committed at the entrance gate of Auschwitz was enough to keep me awake until the end of time," Kent said.
"How can I ever forget the smell of burning flesh that permeated the air?"
The mournful wail of the "shofar," a traditional Jewish ram's horn symbolizing freedom, rang out as participants prayed for the victims near the camp's red-brick entrance and its railway lines to the gas chambers.
"We are in a place where civilization collapsed," Polish President Bronislaw Komorowski told those gathered as he paid respect to the Soviet Red Army troops who liberated the camps.
As night fell, dignitaries and survivors walked along the rails in the shadows of the camp's barbed-wire fence to lay wreaths and candles.
"I thought I'd be incinerated here, never to experience my first kiss, but somehow, a 14-year-old girl, I survived," Halina Birenbaum, 86, told hundreds of dignitaries and fellow survivors, most of them in their eighties and nineties.
The grandson of the Auschwitz commander Rudolf Hoess was among the attendees.
"I can't forgive my father or my grandfather. I'm completely different," Rainer Hoess, who is devoted to fighting anti-Semitism, told reporters.
Earlier Tuesday, French President Francois Hollande and his Czech counterpart Milos Zeman echoed warnings by German Chancellor Angela Merkel and Hollywood mogul Steven Spielberg over violence against Jews in modern-day Europe.
"France is your homeland," said Hollande, who later described as "unbearable" the rise in anti-Semitic attacks, underscored by the Islamist killings of four people at a kosher supermarket in Paris earlier this month.
Anti-Semitic acts in France, home to Europe's largest Jewish population, doubled in 2014 to 851 from the previous year, France's main Jewish group CRIF said Tuesday.
European Jewish Congress chief Moshe Kantor warned that Europe is "close to" a new exodus of Jews, saying "jihadism is very close to Nazism".
Merkel said it was a "disgrace" that Jews in Germany faced insults, threats and violence, as she joined survivors in Berlin on Monday.
And President Barack Obama pledged in a statement Tuesday "never to forget" those murdered by the Nazi regime and voiced concerns over anti-Semitism.
German President Joachim Gauck and Ukraine President Petro Poroshenko were among a host of leaders attending Tuesday's memorial, but Russia, the United States and Israel sent lower-ranking representatives.
Celina Biniaz, now a smartly-dressed 83-year-old, was only a child when as one of 1,200 Jews she was placed on Oskar Schindler's famous list and escaped the death camp to work in a nearby factory.
"I so wish they would settle that problem in the Middle East because I so believe that it has a definite impact on what's happening with anti-Semitism all over Europe," Biniaz, who came from California for the ceremonies, told AFP.
Part of Adolf Hitler's genocide plan against European Jews, dubbed the "Final Solution," Auschwitz-Birkenau operated in the occupied southern Polish town of Oswiecim between June 1940 and January 1945.
Of the more than 1.3 million people imprisoned there, some 1.1 million, mainly Jews, perished, either in the gas chambers or by starvation or disease.
Historians estimate that up to 150,000 ethnic Poles were also held at Auschwitz.
Used as slave laborers, half died at the camp and many others perished while being transported to other camps.
European Roma were also targeted for annihilation. Around 23,000 were deported to Auschwitz. Only 2,000 survived, according to estimates.
The Nazis killed six million of pre-war Europe's 11 million Jews and more than half of its roughly one million Roma. Black Germans, homosexuals, Jehovah's Witnesses and the mentally and physically disabled were also persecuted as "undesirables."
Historical records show that by 1942, the Polish resistance provided Allied powers with eyewitness accounts of the Holocaust. Inexplicably, Washington and London failed to act.
"The debate as to why the Allies did not bomb the supply lines to Auschwitz remains unresolved," survivor Marcel Tuchman told AFP.
"Whether there was a sinister reason behind it or whether it was just tactical, in that they didn't want to divert their air force remains unclear," the 93-year-old said.
"A little bomb in the proper place would have really helped."