Pope Benedict XVI, the head of the Roman Catholic Church, made no direct reference to the controversy surrounding allegations of Catholic priests involved in child sex-abuse cases as he led the Holy Thursday mass in the Vatican City.

The traditional ceremony, which commemorates the last supper of Jesus Christ, is part of holy week, a time of penance when Christians are supposed to confess their deepest guilts and ask for forgiveness.

Benedict used the occasion to urge priests to oppose violence.

"As priests, we are called in fellowship with Jesus Christ, to be men of peace, we are called to oppose violence and trust in the greater power of love," he said.

Special 'significance'

On Wednesday, the pope sent a special message about priests during a weekly address to a massive crowd of the faithful.

"In this year for priests, the Holy Thursday Christ mass, at which priests renew the promises made on the day of their ordination, will take on a particular significance," Benedict said.

"May priests everywhere be conformed ever more closely to Christ as heralds of his message of hope, reconciliation and peace."  

Last month, Benedict criticised Irish bishops for grave errors of judgement in handling the priest abuse cases.

Since then, several European bishops have admitted to mishandlings of the incidents and some have urged victims to consider filing criminal complaints.

Christoph Schoenborn, the archbishop of Vienna and Austria's senior cleric, was one of those who admitted church guilt.

"We confess, that we darkened and betrayed the name of God, which is love.," he said.

"Some of us spoke of the love of God, and did evil to those who most needed protection.

"Again and again, my bad experiences attack me, they grow enormous in front of my eyes."

Article criticised

But the Vatican has also hit back at critics. Just days before the Thursday mass, a senior official of the church issued a statement defending accusations concerning Benedict's handling of sex-abuse cases.

Cardinal William Levada posted an article on the Vatican's official website, criticising the New York Times, a US newspaper, for wrongly using internal documents to find fault with the pope.

The newspaper highlighted a case in which Wisconsin church officials tried to persuade the Vatican to defrock a priest who was believed to have abused as many as 200 deaf boys from 1950 to 1974.

The pope, then Cardinal Joseph Ratzinger, was head of the Vatican's doctrinal office when the case was referred there in 1996.

Levada said the newspaper's article wrongly "attributed the failure to accomplish this dismissal to Pope Benedict, instead of diocesan decisions at the time".