Children are victims of human trafficking. Nearly every third human trafficked victim is a child, according to the United Nations Children’s Fund (Unicef).

According to new data released by Unicef on July 29, about 28% of victims of human trafficking are under 18. In sub-Saharan Africa the number jumps to 64%, and in Central America and the Caribbean it is not much lower at 62%, reported Deutsche Welle (DW), Germany’s international broadcaster.

“Human trafficking is a real threat to millions of children worldwide, especially for children who have to leave their homes and are without protection,” said Unicef Executive Director Henrietta Fore in Cologne, Germany, ahead of the World Day against Trafficking in Persons on July 30.

The situation is especially dire for refugees, who may “feel threatened by the traffickers, or who may not trust the police or public institutions”. They may also fear being “stigmatized” by their community or being returned home. Children are also more likely to be unaware of their rights.

In Rome, Pope Francis used the occasion to say it was everyone’s responsibility to stand against the buying and selling of people, especially children.

“This scourge,” he said, “reduces many men, women and children to slavery.”

The pope called on national governments to increase services and security on the most dangerous migrant routes.