During his homily, Francis also made an appeal against what he called "growing indifference" to the poor, who, he said, are often forced into poverty by injustice.

Francis has used his papacy since 2013 to draw attention to those living on society's margins. The Catholic Church dedicated the day to the world's poor.

"We are part of a history marked by tribulation, violence, suffering and injustice, ever awaiting a liberation that never seems to arrive," Francis said. "Those who are most wounded, oppressed and even crushed, are the poor, the weakest links in the chain."

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