Frenzied crowds of Roman Catholics mobbed the car carrying Pope Francis when he returned to his home continent for the first time as pontiff, embarking on a seven-day visit meant to fan the fervour of the faithful around the globe.
During the pope's first minutes in Brazil, ecstatic believers swarmed around the closed Fiat several times when it was forced to stop by heavy traffic on the drive from the airport to an official opening ceremony in Rio's centre.
A few security guards struggled to push the crowd back in scenes that at times looked alarming. A city official told Globo TV that the pope's driver turned into the wrong side of a boulevard and missed lanes that had been cleared.
Pope Francis looked calm during the frenzy. He rolled down the window on the rear passenger-side of the car where he was sitting, waving to the crowd and touching those who reached inside. At one point, a woman handed the pontiff a dark-haired baby, whom he kissed before handing it back.
After finally making it past crowds and blocked traffic,Pope Francis switched to an open-air popemobile as he toured around the main streets in downtown Rio through mobs of people who screamed wildly as he waved and smiled. Many in the crowd looked stunned, with some standing still and others sobbing loudly.
At the airport earlier, Brazilian president Dilma Rousseff vigorously shook Pope Francis's hand after he descended the stairs following a no-frills charter flight. He made no public statements. The pope was handed two bouquets of white and yellow flowers by two adolescent girls, each of whom he kissed on the cheek.
Reaching the end of the red carpet full of church leaders and other dignitaries, Francis and the Brazilian president paused to be serenaded by a choir of about three dozen young people singing an anthem linked to World Youth Day, an event uniting hundreds of thousands of young faithful from around the globe. Before singing, the youngsters robustly yelled football-like chants in the pope's honour.
It was the first time the Argentine-born Pope Francis had returned to his home continent since his selection as pope in March.
During his stay, the 76-year-old will meet legions of young Catholics converging for the church's World Youth Festival in Rio. More than a million people are expected to pack the white sands of Copacabana beach for ceremonies presided over by Pope Francis. He will also visit a tiny chapel in a rubbish-strewn slum and make a side trip to venerate Brazil's patron saint, Our Lady of Aparecida.
Earlier on the flight from Rome, Pope Francis expressed concern for a generation of youth growing up jobless as the world economy sputters. He warned about youth unemployment in some countries in the double digits, telling journalists there is a "risk of having a generation that hasn't worked".
"Young people at this moment are in crisis," he said.
Anti-government protesters later clashed with police outside a welcoming ceremony for Pope Francis at the Guanabara government palace, but the anger was directed at Brazilian leaders and not the pontiff.
A Vatican official also said that authorities had found a small homemade bomb near a church the pope plans to visit on Wednesday but that it did not appear to be connected to the pontiff's visit.