The parcel bombs had wounded two people at the Swiss and Chilean embassies in Rome, a reminder of Europe's home-grown threats at a time of political instability.
An Italian anarchist group claimed responsibility for parcel bombs on Thursday that wounded two people at the Swiss and Chilean embassies in Rome, a reminder of Europe's home-grown threats at a time of political instability.
A Swiss man was seriously wounded and rushed to hospital. An employee at the Chilean embassy was less seriously hurt. A note was found stuck to his clothing, claiming responsibility for the attack on behalf of the FAI, or Informal Anarchist Federation.
"We have decided to make our voice heard with words and with facts, we will destroy the system of dominance, long live the FAI, long-live Anarchy," said the note, written in Italian, which was released in the evening by the police.
The incidents bore similarities to an episode in Greece last month in which far-left militants sent parcel bombs to foreign governments abroad and to embassies in Athens.
The note was signed by the "Lambros Fountas revolutionary cell" of the FAI, named for a Greek anarchist killed in a clash with Athens police in March. It also made reference to anarchist movements in Chile, Mexico, Spain and Argentina.
"Greece, Italy and Spain have seen the presence of anarcho-insurrectionalist groups that are tightly linked," Italy's interior minister Roberto Maroni said before the note was found. "They are very violent."
The FAI is well known to Italian authorities. Intelligence services said in a report to Parliament last year that it was "the main national terrorist threat of an anarchist-insurrectionalist type." In December 2009 the group claimed responsibility for a bomb that partially exploded in a tunnel under Milan's Bocconi University at 3 am, causing no casualties.
No note was found at the Swiss embassy, but police said the packages that exploded were almost identical.
The explosions came at a time of tension in Italy. Last week saw an anti-government student protest that descended into some of the worst street violence in Rome for many years.
Italian foreign minister Franco Frattini condemned the incidents, which he said were a serious threat to diplomatic missions in Rome. He urged caution and warned against alarmist reactions.
The attacks, like those in Greece, focused attention on Europe's domestic security threats at a time when authorities had otherwise been warning of the risk of attacks by al-Qaeda.
"It doesn't look like a typical jihadi thing. It looks more like the act of a leftist, fringe group," said Stephan Bierling, professor of International Politics at Regensburg University in Germany.
Spending cuts caused by the financial crisis have led to demonstrations and strikes around Europe, and experts expect a rise in political violence by far-left groups.
"Given the similarities with the recent parcel bombs in Greece following anti-austerity protests, this could be a copycat incident by domestic activists," said Samantha Wolreich, European risk analyst at advisory firm AKE.
A Greek police official said they had so far not received a request for help from Italian police. He said Greek authorities had stepped up checks of parcels at airports across the country following the attacks in Italy.
Bomb disposal experts searched the Swiss embassy offices but staff remained in the building following the incident, which occurred at around midday (1100 GMT).
Firefighters conducted checks of the Chilean embassy, in the same prosperous neighbourhood, after the explosion of the package the size of a document. Other inspections were carried out at foreign missions across the Italian capital.
A source in the Rome prosecutors' office said the package in the Chilean embassy had been sent from Italy, while the package in the Swiss embassy had been completely destroyed.
"We are reviewing our security posture in Rome in light of incidents today," US state department spokesperson PJ Crowley said in Washington.
Chilean ambassador Oscar Godoy said there had been no indication that an attack was likely.
"This is an absolutely irrational and brutal act of terrorism," he told reporters.
The explosions follow the discovery of a rudimentary device in an empty underground train in Rome on Tuesday. However, police said that it lacked a detonator and tests showed it contained no explosive.