Former Greek prime minister Lucas Papademos and two other people were hurt after he opened a letter bomb while in his car in central Athens.
Papademos reportedly suffered injuries to his hands and legs after opening the parcel.
He was transferred to Evangelismos hospital along with his driver and a body guard who were also injured.
A police spokesman said the blast occurred while the car was in motion at the junction of Patission and Marnis Street at 6.30 p.m. He said Papademos and two other people were hurt, apparently not seriously but that it was "too early to say."
Bank of Greece Governor Yannis Stournaras visited Papademos in the hospital, referring to a "cowardly attack" in comments to reporters.
The Greek government "condemns unequivocally" Thursday's attack on Papademos, spokesman Dimitris Tzanakopoulos said after visiting Evangelismos hospital.
Doctors said the former premier and the two other people hurt in the blast were "stable and conscious," he told reporters.