Pope Francis says employers who exploit their workers for their own profit are committing a mortal sin.

During his morning homily Thursday, Francis said such labor exploitation is a modern-day form of slavery. He said those who exploit workers are no different than the human traffickers of the past who enslaved Africans and sold them in the Americas.

According to a Vatican Radio transcript of his homily, Francis said: "Living off the blood of people, this is a mortal sin! A mortal sin. And it requires so much penance, so much restitution to be absolved of this sin."

History's first Latin American pope has frequently denounced the injustices of the global economy that he says has impoverished the poor and destroyed the environment while enriching the wealthy few.