Brazil scrambled on Tuesday to beef up security around Pope Francis after he was mobbed by adulating crowds upon his arrival on a landmark visit to the country.
The fervor and, at times, chaos that surrounded the pontiff on Monday reverberated among the organizers of the trip, which began with a raucous reception from throngs of cheering pilgrims who swarmed his car.
Despite heightened security in Rio de Janeiro for Latin America's first pope, legions of Roman Catholics were able to stop his convoy and reach their hands inside his car's open window.
The 76-year-old Argentine appeared delighted by the frenzied crowd as he waved and smiled while bodyguards struggled to keep people at bay. His secretary later admitted being terrified.
The pontiff's visit comes as the country grapples with weeks of violent anti-government protests.
The highlight of his trip to the world's most populous Catholic country will be World Youth Day, a five-day event that kicks off Tuesday.
The pontiff's trip, however, has been overshadowed by persistent demonstrations in the country over political corruption and a failure to provide basic services. Police on Monday also used tear gas and water cannon on hundreds of protesters demonstrating against the $53 million spent on the pope's visit.
The clashes came after the pope met with President Dilma Rousseff at the Rio state governor's palace.
A policeman said they charged at demonstrators after someone threw a Molotov cocktail. Five people were detained and an AFP photographer clubbed on the head by police required three stitches. Further public demonstrations are planned for Friday.
The military had earlier disclosed that troops found and destroyed a homemade explosive device in the bathroom of a parking lot at a sanctuary that the pope will visit in Sao Paulo state this week.
Pope Francis had unnerved local authorities by deciding to leave his armored "Popemobile" behind. He sat in the back of a small four-door car to head from the airport to the city and then climbed on to an open-top jeep to greet more crowds.
"The pope's secretary told me he was terrified, but the pope kept smiling," Vatican spokesman Federico Lombardi told reporters.
The pope has no public events scheduled for Tuesday and will spend time at a hillside private residence.
Pope Francis is bringing his social message of a "poor Church for the poor" but his mission is also to re-energize the faithful. Even in Brazil, his flock is shrinking while Evangelical churches are growing.
Speaking alongside Rousseff, the pope used his first day in Rio to urge young Catholics to "go and make disciples of all nations."
But a poll by Datafolha Institute on Sunday showed just 57 percent of Brazilians now call themselves Catholic, while 28 percent say they are Pentecostal or non-Pentecostal Evangelicals. More than 90 percent identified as Catholic in the country's 1970 census.
World Youth Day, which is expected to attract 1.5 million people, will officially kick off Tuesday with an evening mass led by the archbishop of Rio, Orani Joao Tempesta, on the beach of Copacabana.
But the faithful will have more chances to get close to the pope, who has made a habit of breaking with protocol to better connect with his flock.
On Wednesday, he will visit the Shrine of Our Lady of Aparecida in Sao Paulo state, where the explosive was discovered on Sunday.
Authorities said the device was nowhere near the area the pope and pilgrims will visit. Lombardi described the explosive as "very crude" and insisted that it was no cause for concern.
Pope Francis will return to the crowds of Rio on Thursday, visiting one of the city's sprawling shantytowns before addressing his young flock on an ornate stage on Copacabana.
On Friday, he will walk the Stations of the Cross along the beach, but the Anonymous Rio protest group called for a demonstration near the site to denounce government waste.