Brazilian police found a small homemade explosive in a parking garage near a Catholic sanctuary in the city of Aparecida where Pope Francis is scheduled to visit later this week, a state news service said on Monday (Tuesday NZT).
The explosive, made with a plastic pipe wrapped in tape, was safely detonated by a police bomb squad.
The device was found in the bathroom of a parking structure in Aparecida, a city in Sao Paulo state whose sanctuary honors the patroness of Brazil, Our Lady of Aparecida. It was unclear if the device was related to the pope's visit.
Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil.
Welcomed by a committee of local dignitaries, including President Dilma Rousseff, Francis waved to onlookers before proceeding to a motorcade through Rio's city centre, where local Catholics, visiting pilgrims and the curious were gathered to receive him. The new pope was then scheduled to meet Ms Rousseff and other officials at a government palace nearby.
The trip to the coastal metropolis, a return to his home continent by the former Argentine cardinal, is part of the biennial World Youth Day gathering.
Despite the novelty of a new pope, the visit comes as secular interests, other faiths and distaste for the sexual and financial scandals that have roiled the Vatican in recent years cause many Catholics in Latin America and around the world to leave the Church.
The trip also comes amid growing economic and social dissatisfaction in Brazil, which is still home to more than 120 million Catholics. The unease in June led to the biggest mass protests here in two decades as more than 1 million people in hundreds of cities rallied against everything from rising prices to corruption to poor public services.
In the five months since he succeeded Benedict, Francis has pleased many with his simple style, rejection of luxuries and calls for the Church to advocate on behalf of the poor and causes of social justice. Aboard his plane on Monday, the pope told reporters the world risks losing a generation of young people to unemployment and called for a more inclusive culture.
"The world crisis is not treating young people well," Francis, 76, said. "We are running the risk of having a generation that does not work. From work comes a person's dignity."
Brazilian officials hope that his message of solidarity with the poor and working classes will minimise the possibility of major protests during his visit.
Still, they have deployed more than 20,000 soldiers, police and security officials for the visit. While some of the measures are routine security provided for any visiting head of state, they are compounded by the popular draw of the pope, especially because Francis has said he plans to travel around the city in an open-top vehicle and occasionally mix with the throngs.
Some protests are already planned during the visit, mostly by feminists, gay rights groups and others who disagree with the Church's longstanding social doctrines. Brazil's recent protests, organised through social media by a disparate group of online activists, make other demonstrations likely, even if on a much smaller scale than in June.
Ahead of the visit, however, a festive atmosphere reigned.
Thousands of young pilgrims, many from neighbouring countries and some from as far away as the Philippines, flocked to Rio's sunny seaside during the weekend and endured long lines to visit the city's iconic Christ the Redeemer statue and Sugarloaf mountain, a giant granite monolith.