The package caught fire when it was examined by Italian authorities. The booby-trapped parcel was one of five that were intended for targets across Europe. One reached the office of the German Chancellor, Angela Merkel, and was neutralised by police. Two others, bound for the Europol headquarters and the European Court of Justice, were destroyed in controlled explosions by the Greek bomb squad at Athens airport. A fifth, intended for the French President, Nicolas Sarkozy, was carried by one of two suspects arrested on Monday.
In all, the left-wing group responsible for the attacks, believed to be the Conspiracy of the Cells of Fire, has despatched more than 13 devices and the Greek authorities fear that some have not yet reached their targets.
The Greek Prime Minister, George Papandreou, says he will be "merciless" to those who are trying to rock social peace and hurt the country's image during a very difficult period.