Greek police said they intercepted eight suspect packages at a postal sorting centre in Kryoneri, northern Athens on Monday.
Strict inspection has come into place after letter bombs were delivered to the International Monetary Fund in Paris and the German Finance Minister Wolfgang Schaeuble recently.
A Greek militant group, Conspiracy of Fire Cells, had claimed responsibility for the package sent to Germany which was intercepted on March 15, but did not claim responsibility for the letter to the IMF that exploded in its Paris offices on March 16.
"Eight suspect packages which listed as recipients persons in European countries were located and confiscated today," police said.
A police source later said the packages were intended for officials at the Eurogroup and other global economic institutions.
Greek media report that one of the recipients was Eurogroup President Jeroen Dijsselbloem, but there was no official confirmation.
TRT World's Maria Kagkelidou has more from Athens.
Conspiracy of Fire Cells
Greece has a long history of urban guerrilla group attacks.
Conspiracy of Fire Cells initially conducted arson attacks but turned to bombings in 2009.
The group has become prominent since the economic crisis erupted in Greece, and is accused by police of carrying out more than 150 criminal acts.
In a proclamation in November, the group said that its plan, which it called "Nemesis," was designed to "spread fear into the yards of the homes of our enemy."
In 2011, several of its members, many of them very young, were convicted of "participating in a criminal organisation" and given long prison sentences.
Three years later, the group announced its return and has since been committing sporadic attacks.
The organisation denounces capitalism and consumerism, as well as police repression and worker exploitation.