PARIS (AFP) -- A parcel bomb exploded Thursday at a legal office in central Paris killing a secretary and seriously injuring a lawyer in an attack condemned by French Prime Minister Francois Fillon as barbaric.

Several other people were lightly hurt in the unclaimed blast shortly before 1:00 pm on the fourth floor of a building in the capital.
The prime minister ""condemns in the strongest possible terms the parcel bomb attack which has cost the life of one person and injured several others, one of them seriously,"" read a statement from Fillon's office.
He ""condemns with vigor such barbaric methods,"" the statement added.
President Nicolas Sarkozy once practiced as a lawyer in the building on Boulevard Malesherbes where the blast occurred, but there was no suggestion of a link.
""The motives of the attack are completely unknown for the time being,"" Paris prosecutor Jean-Claude Marin told journalists at the scene.
Interior Minister Michele Alliot-Marie, who cut short a trip to Brussels to return to Paris, said police were keeping an open mind.
""There is no favored theory... It is too early to be able to come to any conclusions. The other activities in the building were clearly identified, so it seems clear that it was someone in the law firm who was the target,"" she said.
The booby-trapped parcel containing two explosive devices was brought by courier to the law firm run by attorney Catherine Gouet-Jenselme, 60, police said.
""The two devices went off when it was opened,"" Marin said.
The secretary who opened the package died and lawyer Olivier Brane, 58, who was nearby, was injured. He was hospitalized but his life was not in danger, Alliot-Marie said.