VATICAN CITY — Pope Francis led Roman Catholics on Sunday in the first worldwide "Holy Hour," in which participants prayed at the same time around the globe for those suffering from war, slave labor, human trafficking, and the economic crisis.

The Vatican asked Catholics to join him between 5-6 p.m. Rome time in what is known as a Eucharistic adoration - praying before a consecrated communion host.

They were asked to gather in cathedrals, neighborhood parishes, and monasteries to pray for two general intentions penned by the Pope, who prayed in St. Peter's Basilica.

One was for those "who still suffer slavery and who are victims of war, human trafficking, drug running, and slave labor" as well as for the "unemployed, the elderly, migrants, the homeless, prisoners, and those who experience marginalization."

The other was for the 1.2 billion-member Church itself and that it be "without stain or blemish," an apparent allusion to scandals that have undermined its credibility, such as the sexual abuse of children by clergy.

A Vatican official said it was "the first time in the history of the Church" that such an event was taking place. The Vatican said it was impossible to estimate immediately how many people took part.