The parcel did not explode, and authorities hope that it will provide information that will help in their investigation. 

Police also responded to other reports of suspicious packages at the Venezuelan and Danish embassies in Rome and possibly other embassies as well December 27.  

But only the Greek embassy package contained an explosive, according to Francesco Tagliente, the chief of police in Rome.  

Late last week, an anarchist group claimed credit for a pair of mail bombings at embassies in Rome, vowing in messages that it plans more such acts to "destroy the systems of domination", the state-run ANSA news agency reported. 

Police said that the Informal Federation of Anarchists -- an offshoot of the Italian Anarchist Federation, or FAI -- claimed responsibility for attacks at the Swiss and Chilean embassies. 

Tagliente said that the packages on December 27, which included a note from the FAI, were "certainly related" to the ones last week. 

Greek authorities stressed that they believed the wave of letter bombs was the work of a home-grown Greek terrorist group that does not have ties to international organizations like al Qaeda.