Investigators see no links between a man who rammed his car into four soldiers guarding a French mosque and "a terrorist network or terrorist act", according to prosecutors.
The man was stopped when a soldier fired and wounded him in the south-eastern city of Valence.
Prosecutor Alex Perrin said: "So far it seems to be the act of an individual."
Mr Perrin said the 29-year-old French citizen of Tunisian descent is a practising Muslim not reported as radicalised.
He was not known to police or justice services and has no psychiatric history.
His motives remain unclear.
France is on high alert after the co-ordinated attacks by Islamic extremists in Paris on November 13.
Mr Perrin said the man claimed in confused comments that he wanted "to kill soldiers because soldiers kill people".
He notably said "Allahu Akbar", or "God is great", which "shows a link with a certain religiosity", Mr Perrin said.
No weapons or explosive devices were found inside the car.
The man, who is still in hospital, could be charged in coming days with "attempted murders against persons holding state authority".
The attacker twice rammed his car into the soldiers guarding the main mosque in Valence, the prosecutor said, charging once then putting his car into reverse to try to ram the soldiers again.
The soldiers fired warning shots and then fired to disable the driver, who was hit in the arm and leg. More than 30 shots were fired.
One soldier was slightly injured in the leg, and a passer-by was hit in the leg by a stray bullet.
France has been in a state of emergency since the November 13 Paris attacks, claimed by the Islamic State group, that killed 130 people and injured hundreds more.
The soldiers by the mosque are part of the reinforced security guarding places of worship and other sensitive sites around France.