Pope Benedict apologised on Saturday to victims of child sex abuse by clergy in Ireland and ordered an official inquiry there to try to stem a scandal gripping the Catholic Church which has swept across Europe.

The pope's moves over abuse at Irish dioceses and seminaries were the most concrete steps taken since a wave of cases hit Ireland, Germany, Austria and the Netherlands but were met with deep disappointment by the victims in Ireland.

In a letter addressed to the people, bishops, priests and victims of child sex abuse in the overwhelmingly Catholic country, the pope did not make specific reference to Churches in other countries, particularly the pope's native Germany.

"You have suffered grievously and I am truly sorry ... I openly express the shame and remorse that we all feel," he said in the unprecedented letter on abuse by Irish clergy, adding:

"I can only share in the dismay and sense of betrayal that so many of you have experienced on learning of these sinful and criminal acts and the way the Church authorities in Ireland dealt with them."

But the pope failed to address widespread calls in Ireland for a radical restructuring of the church there, nor did he say that bishops implicated in the scandal should resign.

Irish victims expressed their deep disappointment.

"We feel the letter falls far short of addressing the concerns of the victims," Maeve Lewis of the group One in Four told Reuters. She said it focussed too narrowly on Irish priests without recognising the responsibility of the Vatican.

"There is nothing i

n this letter to suggest that any new vision of leadership in the Catholic church exists," she said, adding it should have addressed the fate of head of the church in Ireland, Cardinal Sean Brady, whose resignation they want.

In a speech after mass on Saturday in Armagh, Northern Ireland, Brady did not refer to resigning. "I welcome this letter," Brady said.

The pope announced what is known as an "apostolic visitation" of "certain" dioceses, seminaries and religious orders in Ireland.

An apostolic visitation is an inquiry in which inspectors meet bishops, seminary or convent directors and local church officials to review the way matters were handled in the past, to suggest changes and decide possible disciplinary action.

"GRAVE ERRORS OF Judgement"

Benedict singled out Irish bishops for criticism of their handling of abuse cases in the past.

"It must be admitted that grave errors of judgement were made and failures of leadership occurred. All this has seriously undermined your credibility and effectiveness," he said.

He added: "Only decisive action carried out with complete honesty and transparency will restore the respect and goodwill of the Irish people towards the Church to which we have consecrated our lives," he said.

The letter, the first papal document devoted exclusively to paedophilia, follows a damning Irish government report on widespread child abuse by priests in the Dublin archdiocese.

The Murphy Report, published in November, said the church in Ireland had "obsessively" concealed child abuse in the Dublin archdiocese from 1975 to 2004, and operated a policy of "don't ask, don't tell."

In recent weeks, the Vatican has tried to contain damage as the string of scandals over sexual abuse of children by priests spread across Europe.

The latest scandal in Germany is especially sensitive for German-born Benedict, Munich's bishop from 1977 to 1981.

With public opinion in Germany enraged as more cases emerged, the vice president of the Bundestag lower house, Wolfgang Thierse, called for him to apologise on behalf of those responsible.

Last week the head of Germany's Catholic Church apologised to victims of child abuse by priests when he came to Rome for a visit that was transformed into a crisis management meeting.

Archbishop Robert Zollitsch, head of the German Bishops' Conference, briefed Benedict about the situation in Germany, where more than 100 reports have emerged of abuse at Catholic institutions, including one linked to the prestigious Regensburg choir run by the pope's brother from 1964 to 1994.

(Additional reporting by Andras Gergely in Dublin and Tom Heneghan in Paris, editing by Peter Millership)