Pope Francis washed the feet of former mafiosi on Thursday in a prison known for housing inmates who have informed on old mobster allies.
The closed-door visit to Paliano prison outside Rome saw the 80-year-old pontiff kneel before a small group of inmates, pouring water over their feet, drying them with a towel and bending to kiss them in an age-old Easter tradition.
"We are all sinners, we all have our limits and our shortcomings," Francis told the prisoners.
The jail's inmates include some 50 former mafiosi who made deals to provide anti-mafia prosecutors with information in exchange for shorter prison sentences, along with other informers, according to the chaplain.
- Dust and slaves -
The rite, performed yearly on Maundy or Holy Thursday, commemorates Jesus Christ's Last Supper with the apostles.
In Christian tradition, Jesus is said to have washed their feet ahead of the meal in a gesture of humility.
"The feet washing ritual dates back to Roman mealtimes, because the roads were not paved and people entered houses with their feet covered in dust," the grandfatherly Francis explained to the prisoners.
"One of the gestures of welcome made by hosts was to wash their guests' feet. But it would be the slaves that did it. Jesus turned the ritual on its head. He washed them," he said.
"I am not telling you to start washing each other's feet, that would be a joke!
"But I tell you, if you can help, if you can perform a service for a companion here in prison, do it, because this is love, this is what washing feet is: serving others," he added.
In 2014 Francis excommunicated members of the mafia, which he called "the adoration of evil and contempt for common good".
The bishop of Palestrina, Domenico Sigalini, said by choosing turncoats for the ceremony the pope "wants to send a message to those who chose to repent, those usually judged as villains while often showing a personal maturity and an attempt to change".
- Cake in the clink -
The twelve inmates washed by Francis included a Muslim man who is converting to the Catholic faith, three women, an Argentine and an Albanian. Two of the Italians taking part are serving life sentences, the Vatican said.
Four other inmates assisted during the mass.
The jailbirds presented the pope with organic vegetables grown in the prison's allotment as well as cakes they had made, a cross fashioned out of olive wood and white wool cloak.
Thursday's ceremony is part of the run-up to Easter Sunday.
Since his election in 2013, the pope has moved the feet washing ceremony outside the walls of the Vatican and into centres for vulnerable people or those on society's margins.
In his first year he visited a youth detention centre where he performed the ritual on a group of young inmates including two Muslims -- the first Catholic leader ever to do so.
In 2014 he washed the feet of elderly and disabled people, in 2015 he did so in a prison, and last year he chose a migrant reception centre.