Pope Francis has directed Catholic bishops across the world to maintain zero tolerance towards child sexual abuse by the clergy, reported AP. In a letter dated December 28, which was released by the Vatican on Monday, the pontiff condemned the sexual exploitation of children by priests, saying it was “a sin that shames” the clergy.

“Let us find the courage needed to take all necessary measures and to protect in every way the lives of our children, so that such crimes may never be repeated,” the letter said according to Reuters. “Let us adhere, clearly and faithfully, to ‘zero tolerance.’” Begging for forgiveness for such acts performed by priests, the pontiff said, “We join in the pain of the victims and weep for this sin.”

His comments come a day after a priest in Kerala was arrested for sexually abusing an 11-year-old schoolboy on December 21. Father Basil Kuriakose is accused of molesting and sodomising the child. He was arrested under relevant sections of the Indian Penal Code and provisions of the Protection of Children from Sexual Offences Act, 2012.

In 2014, the Pope had set up a commission, comprising a few sexual abuse victims, to advise local churches on how to prevent abuse. Pope Francis also proposed to establish a Vatican tribunal to judge bishops accused of covering up sexual abuse, or even failing to prevent it. However, the proposal has been stalled so far.