THE Pope led the world's Catholics in marking Good Friday amid a sense of growing concern over rebellion against the church's dogmas and the fate of Christians in the Middle East.
The Pope was set to preside over a sung ceremony in St Peter's Basilica overnight to be followed by the Via Crucis (Stations of the Cross) ceremony by the Colosseum, where thousands of Christians were martyred in Roman times.
The Pope, who turns 85 on April 16, appeared frail and tired after returning from a trip to Mexico and Cuba last month but has taken part in Holy Week prayers with his characteristic spiritual vigour.
The Pope on Thursday issued a stern rebuke to the faithful, condemning those who questioned the church over clerical celibacy and the ordination of women.
"Recently, a group of priests in a European country published an appeal for disobedience, giving concrete examples of how to be disobedient," he said. "As Jean Paul II irrevocably said, the Catholic Church did not receive authorisation (to ordain women) from the Lord."
The Pope's comments were a rare response to an "appeal to religious disobedience" launched by a group of Austrian priests last year.
The Pope said the priests were pushing divisive ideas at a time when the church finds itself
"in an often dramatic situation".
This year's celebrations occur amid concerns over the fate of Christians in the Middle East in the face of rising Islamism and violence, especially in Syria, which has a large Christian minority.
Donations from Thursday's mass were for Syrian war victims and the Pope made a donation of $US100,000 ($97,000) to the same cause last weekend.
Senior church figures have voiced concern about Syria recently, calling for a rapid enactment of a UN plan to end the fighting.
Religious news agency I.Media said the Vatican was preparing to announce in coming days that the Pope would travel to Lebanon in September where he is expected to make a plea for peace and religious tolerance.