Pope Francis has claimed Satan is behind the sex abuse cover-up scandal engulfing the Catholic church.
The head of the Catholic church said the Devil "had it in" for bishops "in order to scandalise the people".
Although he did not mention recent sex abuse cover-up allegations directly, the speech seemed to reference the Theodore McCarrick scandal from earlier this year, the Daily Mail reported.
The US prelate was removed and ordered to live a lifetime of penance and prayer by Pope Francis after a church investigation determined that an allegation he groped a teenage altar boy in the 1970s was credible.
Italian Archbishop Carlo Maria Vigano claimed in an 11-page statement Francis lifted unconfirmed Vatican sanctions against the disgraced McCarrick when Benedict XVI was in the papal throne.
As a result the former papal envoy to Washington called for the pope to resign.
Hours after Vigano made the statement to conservative Catholic news media, Francis had told journalists he "won't say a word" about the sensational claims.
Last month Francis called for "silence and prayer" for those involved in the scandal and criticised Irish church authorities for failing to act to sexual over abuse allegations after he met with victims in Dublin.
Although Francis initially has refused to comment directly about Vigano's claims, but nearly every day over the past two weeks his homily at morning Mass has seemed related to the scandal.
Addressing the congregation at the Vatican yesterday, he suggested the "Great Accuser" - or the devil - was behind Vigano's revelations.
He said: "In these times, it seems like the 'Great Accuser' has been unchained and has it in for bishops.
"True, we are all sinners, we bishops. He tries to uncover the sins, so they are visible in order to scandalise the people."
After the allegations against McCarrick were publicised in June, it emerged that it was apparently an open secret - including at the Vatican - and that he routinely molested seminarians and young priests and harassed them.
Bishops should be men of prayer and should know they were chosen by God and keep close to their flock, he added.
In other eyebrow-raising comments on Tuesday, a top aide to both Francis and Benedict said the sex abuse scandal was such a game-changing catastrophe for the church that it amounted to its "own 9/11".
Archbishop Georg Gaenswein told a book presentation that he by no means was comparing the scandal to the nearly 3000 people killed in the US 17 years ago.
But he said the years-long scandal, and recent revelations in the Pennsylvania grand jury report, showed just "how many souls have been wounded irrevocably and mortally by priests from the Catholic Church".
He added: "Today, even the Catholic Church looks full of confusion at its own 9/11, at its own September 11, even though this catastrophe isn't associated with a single date but rather at so many days and years, and innumerable victims."
The same day also saw the announcement that the US delegation would be headed by Cardinal Daniel DiNardo, head of the US Conference of Catholic Bishops, and will also include Francis' top sex abuse adviser, Cardinal Sean O'Malley.
Di Nardo said he wants Francis to authorise a full-fledged Vatican investigation into ex-Cardinal Theodore McCarrick, who was removed as cardinal in July after a credible accusation that he groped a teenager.
The Vatican has known since at least 2000 that McCarrick would invite seminarians to his New Jersey beach house and into his bed.
And yet St John Paul II made him archbishop of Washington and a cardinal in 2001, presumably because Vatican officials impressed by his fundraising prowess considered his past homosexual activity a mere 'moral lapse' and not a gross abuse of power.
DiNardo also said recent accusations that top Vatican officials - including the current pope - covered up for McCarrick since 2000 deserve answers.
Vatican spokesman Greg Burke said DiNardo and O'Malley would meet with Francis on Thursday in the Apostolic Palace.
The summit recalls the April 2002 meeting John Paul called with the senior US church leadership after the sex abuse scandal first exploded publicly in Boston.