The Archbishop of Canterbury has expressed his "deep sorrow" for any difficulties caused by his comments about the Catholic Church in Ireland.
Both Catholic and Anglican clergy criticised Dr Rowan Williams' claim that the Church had lost all credibility because of its handling of sexual abuse of children by priests.
In his first public remarks about the scandal, in an interview for BBC Radio 4, Dr Williams said that what was a colossal trauma for the Church in Ireland had become a problem for the public in general.
"I was speaking to an Irish friend recently who was saying that it's quite difficult in some parts of Ireland to go down the street wearing a clerical collar now," Dr Williams tells the interviewer.
"And an institution so deeply bound into the life of a society, suddenly becoming, suddenly losing all credibility - that's not just a problem for the Church, it is a problem for everybody in Ireland."
The Catholic Archbishop of Dublin, Diarmuid Martin, said he was "stunned". Those working to renew the church did not need or deserve the criticism, he said, and he had rarely felt so discouraged himself, as when he heard it.
"I still shudder when I think of the harm that was caused to abused children. I recognise that their Church failed them," he said.
Dr Williams quickly later phoned Archbishop Martin to express his deep sorrow at the difficulties his remarks had caused.
Dr Williams' apology has pleased the Bishop of Wellington, Dr Tom Brown. "Here, we would not want to be saying things like that - after all I think that all of humanity can make mistakes," he said.
Apologies from Irish, Scottish Church leaders
Last month, Pope Benedict XVI apologised to victims of child sex abuse by Catholic priests in Ireland.
In a pastoral letter he said there had been "serious mistakes" among bishops in responding to allegations of paedophilia.
The head of Ireland's Catholic Church, Cardinal Sean Brady, also apologised for his role in mishandling the case of a serial child abuser; and on Easter Sunday, the Church's Scottish head is expected to apologise to the victims of paedophile priests.
The Church's handling of abuse is likely to be an issue during the Pope's visit to Britain in September.
Belgian bishop denounces church's 'guilty silence'
Belgium's top Roman Catholic bishop has denounced the "guilty silence" of church officials in the paedophile priest scandal that has rocked much of Europe and the United States.
Andre Joseph Leonard, archbishop of Mechelen-Brussel, criticised the church for often worrying more about the reputation of priests than the abused children and of "abominably" exploiting the children.