A parcel bomb exploded today in a TV station controlled by Italian Prime Minister Silvio Berlusconi and a letter burst into flames at Benetton's headquarters as security fears mounted ahead of a Group of Eight summit this week.
Authorities said an envelope containing two live bullets had been sent to the mayor of Genoa, a petrol bomb was thrown against a temporary employment agency in Milan and an explosive device was defused in Bologna.
There were no serious injuries in the incidents, and no indication that they were connected to the three-day G8 summit in Genoa starting on Friday.
But they compounded tensions as thousands of police and soldiers threw up a steel and concrete cordon around the heart of Genoa port where G8 leaders including US President George W. Bush were due to gather on Friday.
A secretary was taken to hospital with minor burns and in shock today after opening the parcel bomb, which exploded in the news offices of Berlusconi's Rete 4 television station on the outskirts of Milan.
Rete 4 is one of three national TV stations owned by Berlusconi's Mediaset empire.