Sunday Mass goers heard Pope Benedict XVI's words of apology as his pastoral letter was read at Catholic churches in Ireland north and south.

The pontiff told victims he was truly sorry for their suffering and admitted bishops had made grave errors of judgment in dealing with paedophile priests, but he stopped short of directly addressing well-documented cover-ups by senior clergy.

But as victims gave a mixed response to the Pope's letter, it was criticised by prominent SDLP politician Declan O'Loan, who described it as inadequate.

"I read the letter with a growing sense that another important opportunity had not been grasped properly. I welcome the apology from the Pope though even that could have been worded more unambiguously," he said.

"However, a full consideration of this issue required a thorough analysis of what went wrong and why it went wrong. That should have led to a clear indication to the Irish Church as to the steps necessary to prevent this kind of abuse, or any other kind of abuse, in the future. In that regard the letter is weak."

The head of the Catholic Church in Ireland, Cardinal Sean Brady, is facing continuing calls for his resignation after he confirmed he had interviewed victims of abuse 35 years ago but failed to alert police. He has argued he fulfilled his role by reporting to his bishop after interviewing the two young victims, who were controversially asked to swear an oath of secrecy. But he faces continuing criticism for failing to tell police about Fr Brendan Smyth, a notorious paedophile who went on to commit crimes against children for a further 18 years.

Mr O'Loan said he was angry at the Church handling of abuse, but indicated that he saw a future in leadership for Cardinal Brady. He said: "There remains an urgent task to be done in fully revealing what has happened in the past and fully responding to that through a fundamental reconsideration of Church culture, systems and structure. Cardinal Brady can still lead that work. However, to do so, he must do so in a way that goes far beyond the Pope's letter, and he needs to show immediately that he has the will and instinct to do this."

Father Kevin Hegarty, parish priest in Kilmore-Erris near Belmullet, Co Mayo, was also critical today of the Pope's letter. He said his parishioners who heard the letter read to them on Sunday wanted to see the Church go further.

"Overall the response would be 'thankfully he's said something at last'. People I've spoken to are appalled and ashamed by the cover-ups and people are just waiting to see what will happen after the Papal letter. Trust won't be rebuilt just by a Papal letter," he said. "There's a huge disillusionment among people going to Church at the moment because of what has been revealed, especially about the cover-ups and they find it very hard to understand. I think the Pope's letter is a small step in the right direction... but it's a long, long journey and it's not the final step."