Greek authorities have intercepted eight suspect packages on Monday that targeted several European officials.
This is the third incident in the space of a week involving Greece and people involved in the bailout talks.
"Eight suspect packages which listed as recipients persons in European countries were located and confiscated today," Greek police said in a text message to journalists, Reuters reported.
A security source told Reuters they were "addressed to officials at economic institutions and companies" at various European countries but would not be more specific.
According to the Financial Times, Jeroen Dijsselbloem, the head of the Eurogroup; Pierre Moscovici, the EU's commissioner for financial affairs, and members of the European Central Bank were among those targeted.
The European Commission declined to comment and referred the issue to the relevant authorities.
Last week, the Greek militant group Conspiracy of Fire Cells claimed responsibility for a parcel bomb mailed to the German finance minister.
The International Monetary Fund also received a letter bomb last Thursday, which injured one person at its Paris headquarters. French authorities are still investigating the incident.
An official within the Greek government, who asked to remain anonymous, told CNBC on Tuesday that he didn't see these incidents as a "big problem." He added that the explosives "were in the category of fireworks."
Greece has been under financial assistance since 2010. It is currently on a third bailout program totaling 86 billion euros ($92 billion).