A bomb exploded at the Swiss and Russian embassies in Athens Tuesday and suspicious packages were detonated by police outside Parliament, the Bulgarian embassy and a courier company, officials said.
No injuries or damage were reported from Tuesday's five small explosions. Police say they suspect that far-left domestic groups are responsible for the wave of attacks that began Monday when four mail bombs failed to reach their targets -- French President Nicolas Sarkozy and the embassies of Mexico, the Netherlands and Belgium.
Government spokesman George Petalotis condemned "those who try in vain to terrorize and disturb the public tranquility."
The bombs were found Monday after one exploded at a delivery service in central Athens, lightly wounding a worker at the delivery company.
Authorities have said the bombs were not particularly powerful, and no link was made with the recently discovered Yemen-based mail bomb plot.
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 armor, 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.
Though a student uprising succeeded in ending military rule in 1974, it also left a legacy of activism and simmering tensions between Greece's security establishment and a phalanx of deeply entrenched leftist groups that often protest against globalization and U.S. foreign policy in the Middle East and elsewhere.
The groups have now evolved into various mainly youth factions that claim to fight trends ranging from globalization to police surveillance cameras. Their impact is usually limited to graffiti and late-night firebomb attacks on targets such as stores and cash machines.