Around 400,000 Roman Catholics have joined a Tuesday evening ceremony on Copacabana Beach in Rio de Janeiro to mark the opening of World Youth Day. The highlight of the festival will be a visit on Thursday by Pope Francis.
The Pope arrived in Brazil on Monday, making his first trip abroad since becoming head of the Roman Catholic Church. His visit is taking place under tight security, after weeks of protests against the government and corruption.
Tuesday's evening Mass at Copacabana Beach was led by Rio's Archbishop Orani Joao Tempesta. He welcomed pilgrims to the five-day festival, which is expected to draw about 1.5 million people from around the world.
The Pope had no public events scheduled for Tuesday and spent time at a private residence. He is expected to greet large crowds at Copacabana on Thursday.
On Wednesday the Pope will visit the Shrine of Our Lady of Aparecida in Sao Paulo state.
A homemade explosive device was discovered there on Sunday, but the authorities said it was of low power and nowhere near the area where the Pope and pilgrims will visit.
Vatican spokesman Federico Lombardi later insisted that the discovery was no cause for concern.
At his request, the Pope will also visit a hospital in Rio on Wednesday and address young people taking part in a drug rehabilitation program.