The explosion occurred on a pavement at around 1130 GMT in a busy neighbourhood where road works were being undertaken, and it set fire to an adjacent building.
A gas leak had been signalled before the explosion.
Passers-by as well as gas workers were among the injured. Two fireman who had been called to the scene were seriously injured, the spokeswoman said.
Nearby buildings were evacuated and French television showed footage of the cleared street strewn with debris from the blast.
Güncelleme Tarihi: 28 Şubat 2008, 16:00