Separate blasts at the Chilean and Swiss embassies in the Italian capital, Rome, that wounded two people were allegedly caused by an Italian anarchist group, according to reports.
Italian police said a note was found on the clothing of a man hurt in the Chilean embassy strike on Thursday, the Reuters news agency reported, saying the note cited the Informal Anarchist Federation (FAI) as being behind the attack.
"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," the note, in Italian, said.|
ANSA, the Italian news agency, also reported that a claim of responsibility by anarchists was discovered in a small box near one of the injured embassy employees, and was being examined by an anti-terrorism police squad.
The blast at the Chilean embassy came just hours after the explosion in the mail room of the Swiss mission on Thursday. Both of the injured were wounded while opening the packages.
A third suspect package was found at the Ukrainian embassy, but was did not appear to contain explosive materials, Yevhen Mitskevich, an embassy spokesman, said.
Gianni Alemanno, Rome's mayor, referred to the blasts as a "wave of terrorism against embassies" and said this was "much more worrisome than a single attack".
"We are working with bomb disposal experts to ensure that no packages can be opened by inexperienced people," Francesco Tagliente, Rome's chief of police, told Reuters.
Al Jazeera's Sabina Castelfranco, reporting from Rome, said the idea that anarchists could be behind the bombs was prominent "but the information is very very sketchy at the moment".
"Investigators say it could be anarchists, the Rome mayor said that it's probably not domestic, that they are following an international lead," she said.
"But really it is too early to establish who is behind this."
The diplomatic mission is situated in a prosperous part of the Italian capital, where many foreign embassies are located.
In a statement, Franco Frattini, the Italian foreign minister, said: "We express our full solidarity with the Swiss ambassador and with all the personnel of this diplomatic representation, which has been the target of a deplorable act of violence that deserves our strongest condemnation."
He said Italian diplomats abroad were urged to take precautions.
The blasts come after a rudimentary device was discovered in an empty underground train in Rome on Tuesday.
However, police said that the device lacked a detonator and tests showed it contained no explosive.