Pope Benedict XVI rebuked Irish bishops Saturday for "grave errors of judgment" in handling clerical sex abuse and ordered an investigation into the Irish church but did not mention any Vatican responsibility.

In a letter to the Irish faithful read across Europe amid a growing, multination abuse scandal, the pope doled out no specific punishments to bishops blamed by victims, and Irish government-ordered investigations, for having covered up abuse of thousands of Irish children from the 1930s to the 1990s.

Ireland's main group of clerical-abuse victims, One in Four, said it was deeply disappointed by the letter because it failed to lay blame with the Vatican for what it called a "deliberate policy of the Catholic Church at the highest levels to protect sex offenders, thereby endangering children."

"If the church cannot acknowledge this fundamental truth, it is still in denial," the group said.

The letter directly addressed only Ireland, but the Vatican said it could be read as applying to other countries. Hundreds of new allegations of abuse have recently come to light across Europe, including in the pope's native Germany, where he served as archbishop in a diocese where several victims have recently come forward. One priest suspected of molesting boys while the future pope was in charge was transferred to a job where he abused more children.

While a cardinal at the Vatican, Joseph Ratzinger penned a letter instructing bishops around the world to report all cases of abuse to his office and keep them secret under threat of excommunication. Irish bishops have said the letter was widely understood to mean they shouldn't report the cases to police.

"You have suffered grievously and I am truly sorry," Benedict said, addressing himself to Irish Catholics who suffered "sinful and criminal" abuse at the hands of priests, brothers and nuns and a botched response by their superiors.

"It is understandable that you find it hard to forgive or be reconciled with the church," he said. "In her name, I openly express the shame and remorse that we all feel."

Benedict used his harshest words for the abusers themselves, saying they had betrayed the trust of the faithful, brought shame on the church and now must answer before God and civil authorities.

"Conceal nothing," he exhorted them. "Openly acknowledge your guilt, submit yourselves to the demands of justice, but do not despair of God's mercy."

Benedict faulted their superiors, the Irish bishops, for having failed "sometimes grievously" to apply the church's own law which calls for harsh punishments for child abusers, including defrocking priests.

But he didn't rebuke them specifically for having failed to report cases of abuse to police, saying only that serious mistakes were made and that now they must prevent future abuse and "continue to cooperate with civil authorities."

"I recognize how difficult it was to grasp the extent and complexity of the problem, to obtain reliable information and to make the right decisions in the light of conflicting expert advice," Benedict wrote.

"Nevertheless, it must be admitted that grave errors of judgment were made and failures of leadership occurred. And this has seriously undermined your credibility and effectiveness."

While the letter doled out no punishment for the bishops, the pope did order a Vatican investigation into some dioceses, seminaries and religious orders. Such a move is undertaken only when Rome considers a local church unable to deal with a problem on its own. The Vatican ordered such an "apostolic visitation" into U.S. seminaries after the U.S. clerical sex abuse scandal exploded in 2002.

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The results of the Irish investigation could lead to further action.

Victims have been demanding that bishops resign, and three Irish bishops have offered to step down. Benedict hasn't accepted the resignations.

Asked why there were no punitive provisions in the letter, Vatican spokesman the Rev. Federico Lombardi noted that the letter was pastoral, not administrative or disciplinary in nature, and that any further measures concerning resignations would be taken by the competent Vatican offices.

Cardinal Sean Brady, the top cardinal in Ireland who himself is under fire for not reporting a notorious abuser to police, welcomed the letter.

"Let us pray that the Holy Father's pastoral letter will be the beginning of a great season of rebirth and hope in the Irish Church," he said.

Three Irish government-ordered investigations published from 2005 to 2009 have documented how thousands of Irish children suffered rape, molestation and other abuse by priests in their parishes and by nuns and brothers in boarding schools and orphanages. Irish bishops did not report a single case to police until 1996 after victims began to sue the church.

The reports have faulted Rome for sending confusing messages to the Irish church about norms to be followed and, in general, for what it called the absence of a coherent set of canon laws and rules to apply in cases of abuse.

In particular, the so-called Murphy report faulted the 2001 secrecy letter penned by then-Cardinal Ratzinger, who headed the Congregation for the Doctrine of the Faith for a quarter-century before becoming pope, making him the most informed Vatican official about the global scale of clerical abuse.

In that role, he denounced the "filth" in the priesthood and initiated what has amounted to a crackdown on predatory priests, demanding a policy of zero tolerance from his bishops. As pope, he has met with American, Australian and Canadian victims of abuse, offering them comfort and apologies.

Nevertheless, reports emerged last week that while he was archbishop of Munich in the 1980s, Ratzinger approved therapy for a priest suspected of molesting boys. The priest was then transferred to a job where he later abused more children. He was convicted in a criminal trial. The archdiocese has said Ratzinger's then vicar general took full responsibility for the transfer.

Lombardi defended Benedict in his handling of the global abuse scandal and said anyone who knows the pontiff's background and history would know he has been a "witness for coherence and correctness" in confronting abuse and a "guide to overcome a past of silence."

Lombardi was peppered with questions about why the German-born pope didn't directly address the German scandal or take the opportunity of the letter to make a more sweeping commentary on the now-global dimensions of the scandal.

Lombardi acknowledged the other cases but said the Irish scandal was unique in its scope. But he said that obviously issues in the letter could be read to apply to other countries and individuals.

"You can't talk about the entire world every time," he said. "It risks becoming banal."

The head of the German bishops' conference, Archbishop Robert Zollitsch, said the letter was a message also for Germany.

"The sexual abuse scandal in Ireland is not just an Irish problem, it is the scandal of the church in many places, it is the scandal of the church in Germany," he said.

A prominent German Catholic activist group, We Are Church, said it respected the pope's efforts with the letter.

But it faulted him for failing to address the fact that abuse is a global and structural problem for the church. "It would be good if there would be a mea culpa from him for all victims around the globe," said spokesman Christian Weisner.

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