VATICAN CITY - In one of the strongest actions since a sexual-abuse scandal began sweeping the Roman Catholic Church in Europe, Pope Benedict XVI on Monday appointed nine prelates, including the archbishops of Boston and New York, to investigate child abuse in Ireland's Catholic institutions.

The pope urged the Irish church to support the investigation, saying it could be a chance for hope and renewal. In a March letter to the Irish faithful, he had promised an inquiry on chronic clerical child abuse in Ireland and decades of cover-ups by church authorities.

Also Monday, the Vatican announced the pope had accepted the resignation of an Irish-born archbishop, Richard Burke, who had led the Benin City Diocese in Nigeria and faced accusations that he had a 20-year relationship with a woman that began when she was 14. He was the latest bishop to resign, as Benedict moves to get rid of bishops who either admitted they molested youngsters or covered up for priests who did.

Child-abuse scandals have caused exceptional trauma in Ireland. An Irish government collapsed in 1994 amid arguments over its failure to extradite a pedophile priest to Northern Ireland. Since 2002, a government-organized compensation board has paid out more than $983 million to 13,000 people abused in Ireland's church-run residential institutions for children.

The investigation in Ireland will deal with the handling of cases of abuse and providing assistance to victims. It will begin in four archdioceses, including Dublin, and then be extended to other dioceses, the Vatican said. It will also look at seminaries and religious houses. The nine investigators will look at the procedures currently in place to prevent abuse and will seek ways to improve them.

The pope invited "all the members of the Irish Catholic community to support this fraternal initiative" and hoped the investigation would be "an occasion of renewed fervor in the Christian life, and that it may deepen their faith and strengthen their hope," the Vatican statement said.

The investigators named by Benedict include the archbishops of Westminster in England, Toronto, and Ottawa.

Archbishop Timothy Dolan of New York will investigate the Irish seminaries as well as the broader issue of priestly formation. Cardinal Sean O'Malley of Boston will investigate the Dublin Archdiocese.

"The Church must be unfailingly vigilant in protecting children and young people," O'Malley said in a statement posted on the archdiocese's website.

U.S. victims of clerical abuse were not impressed by Benedict's move. Some bishops themselves have "troubling" records on confronting abuse, said Barbara Dorris, of the Survivors Network for those Abused by Priests.