(CNN) A day after Pope Francis created an international uproar by saying Catholics nuns had been subjected to "sexual slavery" by the founder of a French order, the Vatican sought to clarify his remarks.

"When the Holy Father, referring to the dissolution of a Congregation, spoke of 'sexual slavery,' he meant 'manipulation,' a form of abuse of power which is reflected also in sexual abuse," said Vatican spokesman Alessandro Gisotti.

The Pope's shocking comments were the first time he has publicly acknowledged the sexual abuse of nuns by Catholic bishops and priests. To date, much of the clergy abuse scandal has focused on minors, who represent the vast majority of cases.

But many Catholics say abuse of vulnerable adults, including nuns and seminarians, has long been a problem in the church. Some hope the church will address the issue at the upcoming meeting on the abuse crisis to be convened by Pope Francis from February 21 to 24 in Rome.

The Vatican's own newspaper, L'Osservatore Romano, last week said abuse of nuns by priests and bishops at times is "made even worse by the fact that abuse of women brings about procreation and is therefore at the origin of forced abortions and children who aren't recognized by priests."

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