|Greek authorities discovered explosives in a package sent to the Bulgarian embassy in Athens on Tuesday [Reuters]
Parcel bombs have exploded at the Russian and Swiss embassies in the Greek capital of Athens, while three more have been detonated outside parliament, the Bulgarian embassy and a courier company, police say.
No injuries or damage were reported following the five small explosions on Tuesday.
"The package went off while police were on their way, but no one was injured," said a police official describing the incident at the Russian embassy.
Vassela Cherneva, spokeswoman for the Bulgarian foreign ministry, told Al Jazeera that a controlled explosion had taken place outside her country's embassy.
"A metal detector had detected that the package had metal inside. The person whose name was on it was contacted, but they knew nothing about it so the police were called," Cherneva said.
"Authorities acted very professionally and the explosion was professional and safe for employees of the embassy and people in the street."
Another booby-trapped parcel exploded earlier on Tuesday at the Swiss embassy in Athens.
Meanwhile, Greek police said that they detonated another suspicious package in a delivery van outside the country's parliament.
Police say they suspect that far-left domestic groups are responsible for the wave of attacks that began on Monday when four mail bombs failed to reach their targets - Nicolas Sarkozy, the French president, and the embassies in Athens of Mexico, the Netherlands and Belgium.
Monday's bombs were found after one exploded at a delivery service in the centre of the capital, lightly wounding a worker at the delivery company.
Two Greek men were arrested on suspicion of plotting the attacks when they were spotted close to the scene of one of Monday's bombings.
Police said they were carrying handguns and bullets in waist pouches, and one wore body armour, a wig and a baseball cap.
One of the two was wanted in connection with an investigation into a radical anarchist group known as Sect of Revolutionaries.
Brady Kiesling, an expert on Greek far-left groups, told Al Jazeera that the explosives were all likely to have been mailed by a little anarchist group that does not aim to cause casualties.
"These are very small crude bombs, homemade, of no particular sophistication. It's an impressive stunt but it's not that dangerous," he said.
"These groups make expressions of solidarity with other anarchists around the world. The anarchists in Greece are a subculture that's been around for decades.
"[The motivation] is partly the austerity cuts, but it's more about an earlier bombing attack that led to some deaths they didn't intend.
"They went into shock for a while. Now they have come back with a new tactic aimed at publicity to put themselves on the map again".