VATICAN CITY - Addressing the clerical abuse scandal from the heart of the Roman Catholic Church, Pope Benedict XVI begged forgiveness yesterday from victims and promised at a Mass to "do everything possible" to protect children.

While symbolic, Benedict's pledge failed to satisfy victims groups that said promises were useless without a clear-cut action plan to root out pedophile priests, expose the bishops who protected them and change the Vatican policies and culture that allowed abuse to continue.

His comments came during a Mass celebrated by 15,000 priests at St. Peter's Square marking the Vatican's Year of the Priest - a year marred by revelations of hundreds of new cases of clerical abuse in Europe, Latin America and elsewhere, as well as cover-ups by bishops and evidence of long-standing Vatican inaction.

It was the first time Benedict had spoken of the crisis from St. Peter's Basilica, the center of the church.