Suspects 'planned Vatican attack'
Islamic extremists suspected over a bomb attack in a Pakistani market that killed more than 100 people had also planned an attack against the Vatican in 2010, Italian prosecutors said.
Wiretaps indicated the suspects were planning a bomb attack at the Vatican and that a suicide bomber had arrived in Rome, p rosecutor Mauro Mura told a press conference in Cagliari, Sardinia.
Mr Mura said the plans never went further and the bomber left Italy, though it was not clear why. He said the wiretaps gave "signals of some preparation for a possible attack".
Italian police said they were arresting 18 suspected extremists, including two purported bodyguards for Osama bin Laden, who allegedly staged attacks in Pakistan and sought to topple the Pakistani government.
At the time of the suspected plot to bomb the Vatican, Pope Benedict XVI was still reeling from the effects in the Muslim world of a 2006 speech in Regensburg, Germany, in which he quoted a Byzantine emperor who characterised some of the teachings of the Prophet Mohammad as "evil and inhuman", particularly "his command to spread by the sword the faith".
While relations with the Muslim world were eventually repaired, tensions flared again in 2011 when Cairo's al-Azhar institute, the pre-eminent theological school of Sunni Islam, suspended interfaith talks with the Vatican after Benedict called for greater protections for Egypt's minority Christians.
More recently, Italian officials have made clear they take seriously the threat of the Islamic State group to conquer Rome and the seat of Christianity. Security has been beefed up at the Vatican and the head of the Swiss Guards has said they are ready but they have no information about an imminent threat.
Pope Francis has said he realises he could be a target but that he fears mostly for the innocent crowds who come to see him every time he is in public.
The investigation was launched in 2005, but Mr Mura said it was slowed when news of the investigation leaked to the media, alerting suspects that they were being watched.
Authorities said some of the suspects sought in the probe were responsible for "numerous bloody acts of terrorism in Pakistan", including a October 2009 explosion in a market in Peshawar in which more than 100 people died.
Telephone wiretaps indicated that two of the suspects were part of a network of people who protected bin Laden in Pakistan, a police statement said.
Police said the aim of the terror network was to create an insurrection against the Pakistani government.
The Vatican downplayed the significance of the planned attack.
Spokesman the Rev Federico Lombardi said: "From what it appears, this concerns a hypothesis that dates from 2010 which didn't occur. It has therefore no relevance today and no reason for particular concern."