New Pope begins tenure with warning

Pope Francis has warned in his first Mass that the troubled Catholic Church risked becoming little more than a charity with no spiritual foundations if it failed to undergo renewal.

Addressing the cardinals who elected him as Latin America's first pope, the 76-year-old Argentinian said on Thursday the Church could "end up a compassionate NGO", using an Italian word that can also mean "pitiful".

"I would like all of us after these days of grace to have the courage to walk in the presence of the Lord," Francis said, amid the splendour of the Sistine Chapel.

He warned the cardinals against "the worldliness of the Devil".

"Walking, building and confessing are not so easy. Sometimes there are tremors," the pope said, in a homily that will be scrutinised for clues to the style of his leadership.

The new head of the world's 1.2 billion Catholics, who was formerly known as Cardinal Jorge Mario Bergoglio, had begun his reign by meeting people in Rome and laying a bouquet of flowers in homage to the Virgin Mary in a basilica.

The pope also prayed at the altar of St Ignatius of Loyola, the founder of the Jesuit order to which he belongs.

He returned to the priests' quarters where he stayed before the conclave and settled his own bill.

On Wednesday night, Pope Francis endeared himself to the crowds in St Peter's Square - and underlined his reputation for humility - when he asked them to bless him before blessing them in return from the balcony of the basilica.

The Vatican's account of his first hours in the top job on Thursday also emphasised Pope Francis's humility, describing how he shunned a special car and security detail provided to take him to the Vatican, travelling instead on a bus with the other cardinals.

He also broke tradition by remaining standing to receive cardinals' acts of homage after his election, instead of sitting in the papal throne.

On Friday, Pope Francis will meet all the cardinals, including those aged over 80 who did not take part in the conclave.

On Saturday he will meet the world's media at a special papal audience, an opportunity perhaps to set out some of his global vision, says the BBC's James Robbins in Rome.

A visit to his predecessor Benedict XVI at his retreat at Castel Gandolfo outside Rome is also planned, but will not take place in the next couple of days.

The visit to Benedict is important, correspondents say, as the existence of a living retired pope has prompted fears of a possible rival power.

Francis will be installed officially in an inauguration Mass on Tuesday 19 March, the Vatican added 

The election of the son of a railway worker, who was considered an outsider, was met with widespread surprise and expressions of hope for change in a Church riven by scandal and internal conflict.

It was also seen as recognition of the Church's power in Latin America, which now accounts for 40 percent of the world's Catholics, in contrast to its decline in Europe.

"The choice of Bergoglio shows that the Church is determined not to remain in mourning for the crisis in Europe but has opened its doors to the revitalising energy of Catholicism's biggest continent," Vatican expert Luigi Accatoli told the AFP news agency.