No one has yet claimed responsibility for the attacks.
The blasts, which happened between 2:30 am and 2:40am local time, blew out windows in neighbouring apartment blocks.
Residents were treated for shock and cuts from flying shards of glass.
“The explosions are of criminal origin,” an unidentified official of the Alpes-Maritimes region told reporters.
The same offices were the target of an attempted bombing by the Corsican separatist group, the Corsican National Liberation Front, in January of this year.