Pope Benedict expressed his "full and unquestionable solidarity" with Jews on Wednesday, after outraging many by rehabilitating a bishop who denies the Holocaust.

Speaking at his Wednesday audience, the German-born pope tried to heal the rift with Jews by saying the attempt to exterminate them in the Holocaust should remain a warning to all humanity.

Recalling his visit to the Auschwitz death camp in 2006, Benedict condemned the "pitiless killing of millions of Jews, innocent victims of blind racial and religious hatred".

British-born Richard Williamson, one of four traditionalist Catholic bishops whose excommunications were lifted on Saturday, has made statements denying the full extent of the Holocaust of European Jews, as accepted by mainstream historians.

Williamson told Swedish television in an interview broadcast a week ago: "I believe there were no gas chambers" and that no more than 300,000 Jews perished in Nazi concentration camps, rather than 6 million.

His interview, taped in November, caused uproar among Jewish leaders and progressive Catholics, many of whom said it threatened 50 years of Christian-Jewish dialogue.

The pope said: "While I renew with affection the expression of my full and unquestionable solidarity with our (Jewish) brothers, I hope the memory of the Shoah will induce humanity to reflect on the unpredictable power of hate when it conquers the heart of man." Shoah is the Hebrew word for the Holocaust.

The pope, who did not mention Williamson, said the Holocaust should remain a "warning against denial and reductionism".

NOT ENOUGH, SAY JEWISH LEADERS

Vatican spokesman Father Federico Lombardi said he hoped it would be "sufficient to respond to the doubts expressed about the position of the pope and the Catholic Church" on the Holocaust. But Jewish leaders said it was not enough.

"We still want to be reassured that the views that Williamson expressed have no place in the Church," said Rabbi David Rosen, head of inter-religious dialogue for the American Jewish Committee.

"We appreciate his sincerity but our concern is that there should not be any room for mixed messages."

Elan Steinberg, vice-president of the American Gathering of Holocaust Survivors and their Descendants, said:

"Clearly the damage remains. As welcome as the pope's remarks are they contain a glaring omission, the demand by the Vatican that Williamson renounce his heinous views."

Elie Wiesel, the death camp survivor, author and Nobel Peace Prize winner, said Pope Benedict had given credence to "the most vulgar aspect of anti-Semitism" by rehabilitating a Holocaust-denying bishop.

In an exclusive interview with Reuters before the pope spoke, he said the Vatican could not have been ignorant of the bishop's views on the Holocaust.

"The Church knows what it does, especially on that level," he said. "For the pope to readmit this man, they know what they are doing. They know what they are doing and they did it intentionally. What the intention was, I don't know."

The chief Rabbinate of Israel sent a letter to the Vatican saying that dialogue with Catholics could not continue as before "without a public apology from Bishop Williamson and recanting his deplorable statements".

It said it would not attend a meeting scheduled for March "until this matter is clarified".