Father Paolo Scarafoni said: “It is indispensable that every priest knows how to discern between demonic possession and psychological problems.” He was opening a four-month course entitled “Exorcism and the Prayer of Liberation” at the Regina Apostolorum pontifical university in Rome.

Father Gabriele Amorth, the Vatican’s chief exorcist, said that there were nine priests carrying out exorcisms in Rome. “I have carried out more than 40,000 exorcisms,” he said. “Satan exists, and targets the young above all. When faith is in decline, idolatry enters in.”

Father Vincenzo Taraborelli, one of the exorcists in Rome, said that the number of exorcisms had more than doubled since he took up his post as a parish priest 15 years ago. “There is always someone sitting in the pews waiting for my help,” he said. Most were aged between 20 and 40 and many were psychologically disturbed. He urged them to see a doctor or psychiatrist, but in other cases he concluded after careful examination that they were “genuinely possessed”.

He said: “Films about exorcism tend to exaggerate, but the victims really do scream and yell in strange, incomprehensible tongues and roll the whites of their eyes.”

He made sure that he was always accompanied by a nun, a lay assistant and “preferably the relatives of the possessed person, to provide support”.

Father Gabriele Nanni, another exorcist, said that the symptoms of possession were “when someone speaks or understands languages they normally do not; when their physical strength is disproportionate to their body size or age; when they are suddenly knowledgeable about occult practices; when they have a physical aversion to sacred things, such as the communion host or prayers”.

Interest in the occult has been boosted by films such as Exorcist: The Beginning, released last year and Scott Derrickson’s The Exorcism of Emily Rose, released this year.

The Italian authorities are alarmed by the rise in the number of Satanic cults, many involving drugs. In February two members of a heavy metal band in Milan called the Beasts of Satan were given prison sentences of 30 and 16 years for the killing of two girls and a youth during “devil worship”.

The Roman Catholic exorcism ritual, adopted in 1614, was updated six years ago. The priest begins with prayers and the sprinkling of holy water. He then makes the sign of the cross while reciting a formula denouncing the Devil.

The exorcism drive has the backing of Pope Benedict XVI, who recently sent greetings to a convention of exorcists and urged them them to “carry on your important work in the service of the Church”.

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