Speaking to parliament on Tuesday, Alfano said jihadists from Isis (Islamic State in Iraq and Syria) may target Italy.
“Italy, as the cradle of Christianity, does not occupy a secondary post in the Islamic war against the West,” he was quoted in l’Occidentale as saying.
The interior ministry however said that the intelligence services “have not registered evidence of Isis plots against Italy.”
Alfano also raised the issue of migrants boats travelling to Italy from North Africa, which he previously said could be used as a route to smuggle terrorists to Europe.
“Surveillance on immigrant boats is very high but the intelligence does not point to a risk of terrorism. Nothing will be underestimated,” he told lawmakers.
Border controls are nonetheless being reinforced, “to avoid the risk that Italy becomes the ‘entry gate’” for jihadists attacking Europe.
Many of the more than 100,000 migrants to have arrived on Italy’s coast so far this year have travelled from Libya, a country the Italian government is monitoring closely.
“Intelligence indicates that instability in Libya supports the training and sending of jihadists to Syria and Iraq,” Alfano said.
A total of 48 people from Italy are known to have joined the Isis ranks. The interior minister said estimates of the total number of militants ranged anywhere from 10,000 to 100,000.
Italy is investing “considerable investigative resources” on internet monitoring, Alfano said, as many jihadists are recruited online.
The Italian government is also working with the EU, international law enforcement agencies Europol and Interpol, and defence alliance Nato to combat the threat posed by Isis.