ROME - A United Nations committee on Wednesday slammed the Vatican for adopting policies that allegedly allowed priests to abuse children with impunity, and asked all priests known or suspected to be abusers to be removed immediately.

The UN Committee on the Rights of the Child (CRC) said in a 16-page report that it was deeply concerned "about child sexual abuse committed by member of the Catholic churches operating under the authority of the Vatican, with clerics having been involved in the sexual abuse of tens of thousands of children worldwide."

Several scandals over child sexual abuse by members of the Catholic Church broke in Europe, Canada, and the United States, mainly since 2002.

The UN watchdog expressed concern because the Vatican has not acknowledged the extent of these crimes and has not taken the necessary measures to address the problem and protect children.

On the contrary, the report pointed out, the Vatican has adopted "policies and practices which have led to the continuation of the abuse by and in the impunity of the perpetrators."

The report came after Vatican officials were questioned in an unprecedented public hearing on January 16 in Geneva, over the reasons why they would not release data on abuse and what the Vatican was doing to prevent further cases.

The Vatican had previously refused to give its data to the UN, by saying that it would give such information only if requested by another state as part of legal proceedings.

The UN committee's report criticized several Vatican's policies, as the practice of transferring well-known abusers from parish to parish or to other countries, "in an attempt to cover-up such crimes," the committee wrote.

It also condemned the "code of silence" imposed on clergy regarding this issue, which resulted in very few cases of child abuse being reported to the authorities when the crimes occurred.

The UN committee recommended the Vatican open its files about members of the clergy who have concealed their abuses, so that they may be prosecuted.

So far, no bishop in the Catholic Church has been sanctioned by the Vatican for covering abusive priests. Bishops were asked to denounce abusers to police only in 2010.

The Vatican reacted to the UN report by saying it would study it carefully, and restated the commitment to protecting children's rights. Yet, it also objected to some remarks.

A Vatican special commission to fight sexual abuse of children was set up in December 2013.