The Vatican has denied press reports that it had received specific warnings from Israeli and US. intelligence services that it was a probable next target of an Islamist attack.

La Repubblica, Corriere della Sera and other Italian papers reported that the CIA and Mossad had warned Italian and Vatican authorities that the Vatican may be a target.

Vatican spokesman Father Federico Lombardi said there were normal contacts among security services but the Holy See had been given no "concrete and specific" information over any risk.

Pope Francis this morning condemned last week's killings by Islamist militants in Paris and urged Muslim leaders to denounce interpretations of religion that use God's name to justify violence.

"Violence is always the product of a falsification of religion, its use a pretext for ideological schemes whose only goal is power over others," the pope said in an annual meeting with diplomats from 180 countries accredited to the Vatican, a speech informally known as his "State of the World" address.

Seventeen people, including journalists and police, were killed in three days of violence that began on Wednesday when gunmen attacked the French satirical weekly Charlie Hebdo.

Francis has repeatedly condemned Islamic State fighters who have killed or displaced Shi'ite Muslims, Christians and others in Syria and Iraq who do not share the group's ideology.

In other sections of his speech, he denounced human trafficking as "an abominable trade" and condemned last month's attack by Taliban militants in which more than 130 Pakistani schoolchildren were killed.

He held up last year's agreement by the United States and Cuba to re-establish ties, which the Vatican helped broker, as an example of how diplomacy and dialogue can build bridges.