Pope Francis is urging Christians to work together to abolish every form of torture, condemning the practice as a grave sin.
Francis told the public in St Peter's Square Sunday he wanted to reiterate his ''firm condemnation of every kind of torture.''
He sought united efforts to work for torture's end and to support victims and their families.
Francis said it was a ''mortal sin, a very grave sin, to torture people'' and noted that Thursday marks the United Nation's day for torture victims.
Torture was a powerful tool of the military regime ruling his native Argentina from 1976 till 1983.
The local church hierarchy then openly sided with the junta.
Francis has been credited with saving lives of political dissidents while a Jesuit priest in Argentina.