(RNS) Pope Benedict XI begged forgiveness for sexual abuse by Roman Catholic priests on Friday (Jun 11), but victims’ groups say they want action, not apologies.

Addressing 15,000 priests gathered from around the world on the final day of the Vatican’s “Year for Priests,” the pope pledged to do “everything possible” to stop “sin within the Church”.

“And so it happened that, in this very year of joy for the sacrament of the priesthood, the sins of priests came to light, particularly the abuse of the little ones,” he said at a Mass before one of the largest gatherings of clergy ever in St Peter’s Square.

“We too beg forgiveness from God and from the persons involved, while promising to do everything possible to ensure that such abuse will never occur again.”

Five bishops in Europe have already resigned from the scandal that has seen prominent cases in Ireland, Germany, Belgium, Austria and the United States in recent months and threatened to engulf the pope himself.

Benedict had already issued a pastoral letter to Irish Catholics in March expressing shame and remorse, and on a recent trip to Portugal he said the greatest threat came from “the sin inside the church.”

A group for victims said the pope’s words were not enough.

“Forgiveness comes after, not during, a crisis,” said Barbara Blaine, president of SNAP, the Survivors Network of those Abused by Priests. She called for an independent inquiry into priests’ abuse and a reduction in the power of bishops.

“The root cause of this horrific and on-going clergy sex abuse and cover-up crisis remains the nearly limitless power of bishops,” she said.

Benedict also promised on Friday that the Church would tighten controls on choosing men for priesthood: “We will do everything we can to weigh the authenticity of their vocation and make every effort to accompany priests along their journey.”

But, speaking at a vigil on Thursday, he dismissed any change to the celibacy rule. After reformers — including women’s groups — had marched on Rome on Tuesday calling for evolution in the Church’s male-dominated structure, the pontiff said celibacy was “an act of faith and fidelity” towards God.