Holocaust survivors and world leaders have held an emotional ceremony in Poland, 60 years after the liberation of the Nazis' Auschwitz death camp.
The site has become the most powerful symbol of the Holocaust
The ceremony began with a train whistle on the railway track that took more than a million people to their deaths.
Thousands gathered in heavy snow next to the site of the German gas chambers, where Jews and others were murdered.
"It seems as if we can still hear the dead crying out," Israeli President Moshe Katsav told the crowd.
"When I walk the ground of the concentration camps, I fear that I am walking on the ashes of the victims."
The Nazi regime murdered six million Jews and many others during what became known as the Holocaust. Auschwitz, the largest of the Nazi camps, where 1.1 million people died, was liberated by the advancing Soviet army on 27 January 1945.
HISTORY OF AUSCHWITZ
Construction began in 1940 on site which grew to 40 sq km (15 sq mile)
At least 1.1 million deaths, one million of them Jewish
Other victims included Poles, Roma (Gypsies), Soviet POWs, homosexuals, disabled people and dissidents
Of 7,000 Nazi guards, 750 were prosecuted and punished after the war
Expressing fears over a resurgence in anti-Semitism in Europe, Mr Katsav questioned whether the memory of the Holocaust had lost its power to deter attacks and insults against Jews.
"The answer is in the hands of Europe's leaders, it is in the hands of the educators and the historians," he said.
Some of the elderly survivors sat wrapped in blankets against the driving snow for up to two hours before the ceremony began.
Some wore tags displaying their prison number - numbers that are still tattooed on their bodies.
"I'm number 4662," said one elderly woman. "We had no names here, and I have a hard time calling myself with my real name here. It's too painful."
Polish President Aleksander Kwasniewski and Russian President Vladimir Putin addressed the crowd. But German President Horst Koehler remained silent, in recognition of Germany's role as perpetrator of the Holocaust.
Touring the camp with survivors before the ceremony, he said: "We have the duty to ensure that something like this never happens again - and we Germans in particular."
As the light began to fade, the Jewish prayer for the dead, the Kaddish was sung. It was followed by Christian prayers - Roman Catholic, Orthodox and Protestant.
Then, former inmates and veterans of the Soviet Red Army led a candle-lighting ceremony to remember the dead.
Flames were lit along the railway tracks and the evocative sounds of a whistle, a stopping train, and a door being flung open, were played over loud-speakers.
Other world figures at the ceremony included US Vice-President Dick Cheney and UK Foreign Secretary Jack Straw.
In the nearby Polish city of Krakow, before the ceremony in Auschwitz, Mr Putin spoke out against anti-Semitism and admitted that it was a problem in his country.
"Even in our country, in Russia, which did more than any to combat fascism, for the victory over fascism, which did most to save the Jewish people, even in our country we sometimes unfortunately see manifestations of this problem and I, too, am ashamed of that," he said.
French President Jacques Chirac, opening an exhibit in honour of French victims, said his country must bear its responsibility for the deportation of Jews from Nazi-occupied France.
In the German capital, Berlin, parliament held a special ceremony including an address by a German-Jewish camp survivor, Arno Lustiger, and the readings of poems by a man murdered in Auschwitz.