Pope Francis has appealed to governments worldwide to act to defeat the "plague" of human trafficking.
"We all can and must collaborate by denouncing the cases of exploitation and slavery of men, women and children," he said, speaking after the Angelus in Rome.
He said: "I thank all those who fight on this front, especially many religious. I especially appeal to the governments, so that the causes of this plague are resolved and the victims protected."
His remarks came two days after the World Day against Trafficking in Persons, on the feast day of Saint Josephine Bakhita. Pope Francis led the crowds in St Peter's Square in reciting the prayer of St Bakhita, which includes the lines: "As a child you were sold as a slave and you had to face untold difficulties and sufferings. Once freed from your physical slavery, you found true redemption in the encounter with Christ and his Church."
At the same time, the Archbishop of Westminster Cardinal Vincent Nichols delivered the closing homily at the latest regional conference of the Santa Marta Group, which took took place in the Pope's birth nation of Argentina.
Cardinal blesses pilgrims at the national shrine in Lujan after mass. Photo: Alexander Des Forges
Preaching in the Basilica of Our Lady of Lujan, delivered simultaneously by a local bishop in Spanish, Cardinal Nichols said: "There is one particular darkness I wish to draw to your attention, as it is the darkness that has brought me here. It is the darkness of human trafficking, of modern day slavery.
"There are more than 40 million people in our world today locked in this darkness, deprived of liberty, of identity, of adequate food and shelter. They have been tricked, deceived and traded, as if they were no more than an object for sale and use. Human trafficking occurs in every country, probably in every city and town.
"It is, in the words of Pope Francis, 'a wound in the flesh of humanity' 'A great wound in the Body of Christ'."
He explained how the Santa Marta Group, of which he is president, us working with the Argentinian Federal Police, under the leadership of General Commissioner Nestor Roncaglia, seeking to build an effective partnership between those forces and the resources of the Church.
"Today I ask all of you to support us with your prayers, with a growing awareness of the realty of human trafficking and slavery in your midst and with a readiness to help in this work."