New data released by UNICEF on Sunday showed that about 28 percent of victims of human trafficking are under 18. In sub-Saharan Africa the number jumps to 64 percent, and in Central America and the Caribbean it is not much lower at 62 percent.

"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 Monday.

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.

Pope: Everyone must take a stand

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 in Rome, "reduces many men, women and children to slavery."

The pope too highlighted the increased risk for refugees, saying "the routes of migration are also often used by traffickers and exploiters to recruit new victims of trafficking."

Francis encouraged national governments to increase services and security on the most dangerous migrant routes.

es/aw (AFP, dpa, KNA)