Greek police said on Saturday they arrested a man they believe was involved in mailing parcel and letter bombs to targets including ex-Greek prime minister Lucas Papademos and former German finance minister Wolfgang Schaeuble.
In March, police intercepted eight suspect packages at an Athens sorting office after the dispatch of booby-trapped parcels to the International Monetary Fund in Paris and the German Finance Ministry in Berlin.
One parcel, mailed to Schaeuble, was intercepted by the ministry's mail department. A letter addressed to the IMF exploded, slightly hurting an administrative assistant.
"The anti-terrorism service arrested a 29-year-old male following a warrant ... related to parcel bomb dispatches," police said in a statement.
Police searched the suspect's apartment in Athens and found two pistols, bullets, a timing device and explosive materials in travel bags, a police official said.
"Police had spotted him in videos bringing parcels to the post office on five different occasions," the official said, declining to be named.
Papademos, who as prime minister from 2011 to 2012 agreed to punishing austerity measures to secure a bailout at the height of Greece's financial crisis, was injured when an explosive device detonated as he opened his mail in May.
The attack, which remains unclaimed, had a similar methodology to that used by Conspiracy of Fire Nuclei, a far-left group which in March mailed an explosive device that injured a secretary at the International Monetary Fund in Paris.
The group also claimed responsibility for a letter bomb, also sent from Greece, discovered at the Berlin offices of Germany's then finance minister Wolfgang Schaeuble.
The bombs contained gunpowder typically used in firecrackers, police said.
Eight other letter bombs, including those addressed to European Economic Affairs Commissioner Pierre Moscovici and then Eurogroup chief Jeroen Dijsselbloem, were intercepted in the aftermath of the Athens attack.