Pope Francis has said he takes personal responsibility for the “evil” of priests who raped and molested children, asking forgiveness from victims and saying the Church must be even bolder in its efforts to protect the young.

It was the first time a Pope has taken personal responsibility for the sex crimes of his priests and begged forgiveness.

Francis made the off-the-cuff remarks after coming under criticism from victims’ advocacy groups for a perceived lack of attention to the sexual abuse scandal and continuing demands that he sanction bishops who covered up for paedophiles.

He delivered the comments to members of the International Catholic Child Bureau, a French Catholic network of organisations that protects children’s rights. Sitting with them in his library, Francis spoke slowly and softly in his native Spanish, deviating from his text.

“I feel compelled to take personal responsibility for all the evil that some priests, many – many in number, (although) not in comparison with the totality – to assume personal responsibility and to ask forgiveness for the damage caused by the sexual abuse of the children,” he said.

“The Church is aware of this damage,” he continued. “We don’t want to take a step back in dealing with this problem and the sanctions that must be imposed. On the contrary, I think we must be even stronger. You don’t play around with the lives of children.”

No Pope has ever taken personal responsibility for the tens of thousands of children who were molested by priests over decades as bishops moved them from parish to parish rather than reporting them to police.

Pope John Paul II denounced priests who hurt children, saying there was no place for them in the priesthood. Pope Benedict XVI expressed sorrow and regret to victims, met them and even wept with them. But neither ever took personal responsibility for the scandal or begged forgiveness as Francis did.

Last month, Francis named the initial members of a commission to advise him on best practices to combat sexual abuse in the Church. Half of them are women and one, Marie Collins, was assaulted by a priest as a child.

Irishwoman Ms Collins, who became a well-known activist in the fight for victims’ justice, had previously called on Benedict to ask personal forgiveness for the scandal and those church leaders who put loyalty to the church ahead of the safety of children.

The Vatican has said Ms Collins and the other members will draft the statutes of the commission and will look into the legal “duties and responsibilities” of church personnel, a suggestion that they might take up the critical question of disciplining complicit bishops. Church law provides for sanctions if a bishop is negligent in carrying out his duties, but to date no bishop has been disciplined for protecting an abuser.

Though unclear, Francis’s comments about the “sanctions that must be imposed” could similarly be a reference to the need to make bishops accountable.

Francis named the commission members after coming under fire for taking no action since the commission was announced in December. Victims’ groups also have been irked that he has not met survivors and recently told a newspaper that the church had been unfairly attacked for its abuse record.