Authorities are investigating after a device exploded outside of a carabinieri barracks on the outskirts of Bologna, hours before Prime Minister Matteo Renzi was due to visit the city.<br /><br /> Nobody was hurt in the blast, and Italian news agency ANSA reported 10 officers were sleeping inside the building at the time of the explosion.<br /><br /> Renzi is campaigning a week before Italians vote on a referendum on constitutional reform, but it’s not clear if the blast is linked to the issue.<br />
