Pope sports bruised chin at new cardinals ceremony

Pope Francis has led a ceremony in St Peter's Basilica to install 21 new Catholic cardinals with what appears to be a bruised chin. The Vatican said it would not comment on the matter.

Francis, who turns 88 this month, appeared otherwise on good form, leading a ritual-filled ceremony on Saturday to elevate churchmen from 17 countries to the College of Cardinals, the elite group that will one day elect his successor.

A purplish blotch could be seen on the right side of the pope's face, around his lower chin and upper neck. The Vatican's press office said it would not comment on what had happened.

Francis, pope since 2013, has suffered occasional bouts of ill health in recent years, and now uses a wheelchair due to knee and back pain.

Cardinals are the highest-ranking officials in the 1.4-billion-member Catholic Church beside the pope. At the pontiff's death or resignation, cardinals under the age of 80 are tasked with entering a conclave and choosing the next pope.

Francis has now installed about 80 per cent of the prelates who will elect the next pope, increasing the likelihood that the next pontiff might share his vision for a Church that is more inclusive and engaged with the wider world.

Francis, originally from Argentina and the first pope from the Americas, has focused on strengthening geographic diversity among the cardinals.

At least 67 countries now have cardinals who can vote in a conclave, according to Vatican statistics, compared to fewer than 50 when Francis was elected.

The newest appointees come from countries including Peru, Argentina, Japan, the Philippines, Algeria, India and Serbia.

In his homily for Saturday's service, Francis said the new cardinals "come from different backgrounds and cultures", urging them to be "witnesses of fraternity, artisans of communion and builders of unity".

Archbishop Ignace Bessi Dogbo, one of the new cardinals, praised the pope's efforts to boost geographical diversity.

"Having cardinals from every part of the world truly translates the universality of the Church," Bessi Dogbo, from Abidjan in the Ivory Coast, told Reuters.

Italy remains the country with the most cardinals, counting 17 under the age of 80. Four of those were installed on Saturday, including the archbishops of Turin, a northern business hub, and Naples, the country's third-largest city.

Among the other new cardinals, one is a Belgian friar serving as archbishop of the Tehran-Isfahan archdiocese in Iran. Another is a Ukrainian Greek Catholic ministering in Australia.