Four women who were forced into sex slavery and later freed met Thursday with Pope Francis at an international conference on human trafficking held at the Vatican to combat what the pontiff called a "crime against humanity."
After a private meeting with the victims, the pope joined church officials and police chiefs from 20 countries, including the U.S., England, Thailand and Nigeria, in an effort to build global cooperation to fight the problem.
"Human trafficking is an open wound on the body of contemporary society," the pope told the conference. "I exhort the international community to adopt an even more unanimous and effective strategy against human trafficking, so that in every part of the world, men and women may no longer be used as a means to an end."
The Catholic church, citing International Labour Organization estimates, calculates that 2.4 million people are trafficked at any given time, with traffickers receiving more than $32 billion a year.
Cardinal Vincent Nichols, archbishop of Westminster, said only 1 percent of those trapped in modern human slavery have been rescued, and it has never been more widespread. Nichols served as chair for the conference, which was organized by the Bishops' Conference of England and Wales.
"There is an endless supply of stolen bodies among the poor and desperate in the world," Nichols said. "They are not free. They are slaves."
Sir Bernard Hogan-Howe, London's Metropolitan police commissioner, said British police have been working with church officials to free victims of trafficking and police have successfully prosecuted 300 cases in the past three years.
With the pope's support, he said, there is potential to collaborate in countries around the world.
"Different jurisdictions can work across boundaries," Hogan-Howe said. "We are building networks with the Catholic church and enforcement agencies. We are not going to give in."