In fact, Rome represents an easy target for terrorists. According to the local media, the government's plan focuses on the overlook of monuments, crowded places like the Colosseum, the embassies and the subways.

Upon a specific alert of the anti-terrorism unit, a large police operation is expected to be carried out in the capital against an extremist cell, composed of some 10 people who would huddle in a flat in the city outskirts, the local media reported.

Italy has kept on severe border security checks, implemented since Paris' killing of last November in the frame of Schengen Treaty, which allows derogations, within temporal limits, to the free passage of people between the member states.

Since the beginning of 2015 the Italian police conducted 2,249 physical searches of persons linked with extremist movements and arrested 396. The government has decided to maintain the alert level at the current degree.