Primate of All Ireland Cardinal Sean Brady reads out the pastoral letter from the Pope to worshippers at St Patrick's Cathedral in Armagh, Northern Ireland, on Saturday. (Peter Morrison/Associated Press)Pope Benedict XVI has released a letter apologizing for years of physical and sexual abuse suffered by Irish children at the hands of priests.

The seven-page letter, published in Rome Saturday, has various sections addressed to the victims, their parents, the abusers, church leaders and the Irish faithful as a whole.

The letter, to be read at Sunday mass, rebukes church leaders for "grave errors of judgment" by failing to respond adequately to allegations of abuse.

“Your trust has been betrayed and your dignity has been violated," the Pope told victims. “I am truly sorry. I know that nothing can undo the wrong you have endured."

The Pope said he felt "shame and remorse" over what the victims have endured and praised their courage in speaking out about their abuse. He also acknowledged that in many cases, no one listened to their complaints.

"You have suffered grievously and I am truly sorry," he said.

Benedict called the abuse carried out by priests "sinful and criminal." He said those responsible must answer for their acts before God and before properly constituted tribunals.

He said many factors gave rise to the problem, including "insufficient human, moral, intellectual and spiritual formation in seminaries and novitiates," a tendency in society to favour the clergy, and a misplaced concern for the reputation of the church and the avoidance of scandal.

"Today is a very historical day for the Catholics of Ireland," said Cardinal Sean Brady, the top cardinal in Ireland who himself is under fire for not reporting a notorious abuser to police.

"In the name of the church, Pope Benedict openly expresses the shame and remorse that we all feel about the abuse that has occurred," said Cardinal Brady, who read the letter Saturday to worshippers at St. Patrick's Cathedral in Armagh, in Northern Ireland.

One in Four, the victims' group, said a new church leadership is necessary in Ireland for the church to regain its credibility.

"In relation to the Irish bishops, the Pope acknowledges their failings, but situates them in failures to adhere to canon law," the group said. "There is no appreciation that the law of the land supersedes canon law, and that the Catholic bishops, like any other citizens, are obliged to abide by Irish law."

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.

With files from The Associated Press