Italian police were on Tuesday investigating whether an attempted parcel bombing at the Greek embassy in Rome might have been carried out by an anarchist group that targeted two embassies last week.
Investigators said on Monday the device at the Greek embassy in Rome bore the hallmarks of a similar attack by anarchists on the Chilean and Swiss missions last week.
The package was "similar to those that exploded last week in the Chilean and Swiss embassies," Italian police spokesman Salvatore Cagnazzo told AFP.
"The mail worker at the embassy opened it but it didn't go off," he said, adding that the package was then defused by bomb disposal experts.
The explosive device was contained in a large padded yellow envelope with a CD case inside and was intended to detonate when opened.
"There's an anarchist group, a terrorist group that wants to send a signal on an international level," the mayor of Rome, Gianni Alemanno, told reporters, adding that the city was now on "maximum vigilance."
The interception of the parcel bomb for the Greek embassy was followed by around 10 false alarms at other foreign embassies around Rome.
Greece's ambassador to Italy, Michael Cambanis, was quoted by La Repubblica daily on its website as saying that the parcel bomb had "arrived on Friday but no one opened it because of the Christmas holidays."
A police source in Athens told AFP that cooperation between Italian and Greek police was "closer" after the discovery of the package, while a justice ministry source said: "Italy's judicial authorities have sought Greece's help to determine possible links between Italian and Greek militant groups."
Last Thursday two parcel bombs exploded at the Chilean and Swiss embassies in Rome, injuring a Swiss mail worker and a Chilean diplomat.
Prosecutors on Monday said that their inquiry for suspected "terrorism" over last week's bombs would now include the Greek embassy package.
Last week's blasts were claimed by an Italian anarchist group calling itself the Informal Federation of Anarchy, or FAI under its Italian acronym.
Investigators have said they believe the claim is "reliable".
"We have decided to make our voice heard with words and deeds. Let us destroy the system of domination... Long live anarchy," read a charred note found at the scene of the Chilean embassy blast.
The statement was signed by the "Lambros Fountas Cell" -- a reference to a Greek far-left activist killed in a shoot-out with police in March 2010.
In a suspected anarchist far-left plot in Greece last month, bombs were sent to foreign embassies in Athens and European government leaders.
More than a dozen packages containing explosives were sent in that plot, prompting Greece to suspend international mail for two days. At least four of the packages ignited or exploded, slightly injuring one person.
But the head of Italian police, Antonio Manganelli, on Monday said there was no apparent link between the attacks in Greece and the ones in Rome.
"So far no elements of material links between the wave of parcel bombs in Greece last month and the recent action in our country have emerged," Manganelli was quoted by ANSA news agency as saying.
The United States meanwhile said it was reviewing security at its embassies worldwide and had told its staff to be vigilant when opening mail.
"In Rome, we are monitoring the situation with local law enforcement," said US State Department spokesman Mark Toner.
The FAI has claimed around 30 low-key attacks in Italy in recent years, starting with two small bombs set off in a rubbish bin outside the home in Bologna of then European Commission chief Romano Prodi in 2003.
The targets have been mainly police, prison authorities, immigrant detention centres and European Union institutions. Last week's bombs are believed to be the first attack claimed by the FAI to have injured someone.