Ex-pope Benedict XVI's condition remains stable, the Vatican said Friday, as Catholics prayed for the 95-year old former pontiff whose health has seriously deteriorated.
The German, who in 2013 was the first pope since the Middle Ages to resign as head of the worldwide Catholic Church, has become increasingly fragile over the years.
Pope Francis said Wednesday his predecessor, whose birth name is Joseph Ratzinger, was "very ill".
On Friday, the Vatican said his condition was "stable," adding that Benedict had rested well overnight and taken part in a mass held in his bedroom.
Benedict moved out of the papal palace and into a former convent within the Vatican when he retired.
Francis called Wednesday for people to pray for him, before visiting him at the Mater Ecclesiae monastery.
The Vatican later confirmed the ex-pope's health had worsened "due to advancing age", while a Vatican source told AFP it began deteriorating "about three days ago".
"It is his vital functions that are failing, including his heart," the source said, adding that no hospital admission was planned, as he has the "necessary medical equipment" at home.
The Rome diocese was set to offer a special mass for Benedict at the Basilica of St. John Lateran later Friday.
- 'Gratitude' -
In Germany, in the church of St Oswald in Marktl am Inn, where the former pope was baptised, a photo of Benedict was set up on a tripod next to a baptistery.
Photos from his 2006 trip to the town line the walls. A red candle burns on the floor. Onlookers occasionally enter the white building, topped by a black bell tower.
One of them, Tobias Ferstl, 43, prayed with his eyes closed for several minutes in front of the photograph of Benedict.
"I was passing through, so I decided to stop by the birthplace of the Pope Emeritus," the devout Catholic, an altar server at Regensburg Cathedral, told AFP.
"I don't feel any great sadness or astonishment, but rather gratitude," he said, despite a few tears filling his eyes. Benedict was "a gentle person", he said.
At Saint Peter's Square at the Vatican, tourists and pilgrims taking selfies in front of the Christmas tree and nativity scene contrasted with the few journalists on standby in case of a death announcement.
"He was a great pope, perhaps misunderstood by some in the Catholic world, but he served the Church. He produced extraordinary homilies and writings," Italian Carmelo Dellisanti told AFP.
- 'A difficult time' -
Benedict was 78 when he succeeded the long-reigning and popular John Paul II in April 2005.
His eight-year pontificate was marked by multiple crises, including the global clerical sex abuse scandal, which has dogged him in retirement as well.
A damning report for the German church in January 2022 accused him of personally having failed to stop four predatory priests in the 1980s while archbishop of Munich.
Benedict has denied wrongdoing, but in a letter released after the report, asked "for forgiveness".
"I think he had a difficult time as pope, because of the paedophilia scandal, and he never really wanted to be pope, so it would be nice if he went to heaven," said 30-year old German Annika Hafner.
Benedict has appeared increasingly frail in recent months, using a wheelchair, but was still receiving visitors.
In photos from on December 1, he appears frail and visibly weakened.
The last public video of him, released by the Vatican in August, shows a thin man with a hearing aid who can no longer speak, but whose eyes are still bright.