The Hellenic Police was on Thursday coordinating with ELTA, the Greek postal service, in a bid to ensure that no further dangerous packages leave the country after parcel bombs were sent from Greece to German Finance Minister Wolfgang Schaeuble and the offices of the International Monetary Fund in Paris.

The parcel bomb that arrived at the IMF’s Paris office detonated, slightly injuring an employee there, on Thursday.

That came a day after a similar bomb arrived at Schaeuble’s office but was defused before it could cause any injuries or damage.

Early on Thursday, the guerrilla group Conspiracy of the Cells of Fire claimed responsibility for sending the package to Schaeuble. In a statement on an anarchist website, the group said it “will continue stronger.” “Nothing is over,” it said, adding that it would provide more details in a proclamation to be issued in due course.

Citizens’ Protection Minister Nikos Toskas confirmed on Thursday evening that the bomb sent to the IMF’s Paris offices had been sent from Greece too. However, there had been no claim of responsibility for the Paris bomb by late Thursday.

Toskas said French authorities told him the sender cited on the package sent to the IMF’s office was Vassilis Kikilias, the spokesman for conservative New Democracy and Toskas’s predecessor at the ministry.

Similarly, German authorities had told their Greek counterparts on Wednesday that the parcel sent to Schaeuble bore the name of another member of ND, Adonis Georgiadis, as the sender.

Sources indicated that the bombs were similar, both comprising gun powder.

ELTA was on Thursday examining its security equipment at Athens International Airport to determine how the packages slipped through.

The attacks provoked condemnation from the head of the IMF, one of Greece’s international creditors, and from the French government.

IMF chief Christine Lagarde denounced “this cowardly act of violence” and reaffirmed “the IMF’s resolve to continue our work in line with our mandate.”

French President Francois Hollande said French authorities would trace the “persons responsible, and we will do it with tenacity, perseverance and until the end,” adding, “I want to tell all those who work for this great institution that we are by their side.”