German-born Pope Benedict XVI, who grew up during Hitler's rise to power, condemned the Nazi attempt to exterminate Jews on Wednesday as a "project of death" that will remain forever an indelible stain on human history.

In his strongest comments on the Holocaust since his election in April, the 78-year-old Pope spoke about a Biblical psalm recalling the destruction of Jerusalem in the Old Testament and the Babylonian exile of Jews.

Addressing thousands of pilgrims at his weekly general audience in St Peter's Square, the Pope said God, as the ultimate arbiter of history, knows how to listen to "the cries of the victims," even if they are sometimes bitter towards him.

"It was almost a symbolic foretelling of the extermination camps in which the Jewish people were subjected to as part of infamous project of death which remains an indelible shame on the history of humanity," he said.

Benedict has in the past condemned the evil associated with the Nazis in his homeland. During his trip to Germany in August, he said Germans will always have to acknowledge it with shame and suffering.

The pope served briefly in the Hitler Youth during the war when membership of the Nazi paramilitary organization was compulsory, although he was never a member of the party and his family opposed Hitler's regime.

The pope has made relations between Catholics and Jews one of the priorities of his pontificate, meeting Jewish leaders and visiting the main synagogue of Cologne during his August trip to Germany.