Pope admits priests, bishops sexually abused nuns

"There are some priests and also bishops who have done it," the pontiff said in response to a journalist's question on the abuse of nuns, speaking on the return flight from his trip to the United Arab Emirates.

The papal admission followed a rare outcry last week from the Vatican's women's magazine over the sexual abuse of nuns by priests and religious sisters feeling forced to have abortions or raise children not recognised by their fathers.

The issue hit the headlines last year after a nun accused an Indian bishop of repeatedly raping her in a case that triggered rare dissent within the country's Catholic Church.

Francis said the problem could be found "anywhere" but was prevalent in "some new congregations and in some regions".

"I think it's still going on, because it's not something that just goes away like that. On the contrary," he added.

He said the Church has "suspended several clerics" and the Vatican has been "working (on the issue) for a long time".

"I don't want to hear it said that the Church has not got this problem, because it has.

"Must we do more? Yes! Do we want to? Yes!" he said.

The February issue of "Women Church World", a supplement distributed with the Vatican's Osservatore Romano newspaper, warned that nuns have been silent over abuse for decades for fear of retaliation.

It said the Vatican received reports of priests abusing nuns in Africa in the 1990s.

"If the Church continues to close its eyes to the scandal -- 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 recognised by priests -- the oppression of women in the Church will never change," editor Lucetta Scaraffia wrote.