German-born Pope Benedict XVI, visiting Auschwitz as "a son of the German people," denounced Sunday the "unprecedented mass crimes" of the Holocaust, and underlined the reality of Hitler's campaign to wipe out European Jews.

"To speak in this place of horror, in this place where unprecedented mass crimes were committed against God and man, is almost impossible — and it is particularly difficult and troubling for a Christian, for a pope from Germany," he said.

"In a place like this, words fail; in the end, there can be only a dread silence," he said, "a silence which itself is a heartfelt cry to God: Why, Lord, did you remain silent?"

He said that just as his predecessor, John Paul II, had visited as a Pole, he came as "a son of the German people."

"The rulers of the Third Reich wanted to crush the entire Jewish people, to cancel it from the register of the peoples of the earth," he said. "By destroying Israel with the Shoah, they ultimately wanted to tear up the taproot of the Christian faith and to replace it with a faith of their own invention."