French police were searching for a driver who hit an army patrol in a Paris suburb, injuring six soldiers.
The anti-terrorist section of the Paris prosecution service was investigating Wednesday's incident, the prosecutor's office said.
Three of the six soldiers were "more seriously" injured, Defence Minister Florence Parly said, but their lives were not in danger.
The incident took place in the inner Paris suburb of Levallois-Perret at about 8am local time, Parly said.
The soldiers were taking part in Operation Sentinelle, under which 10,000 troops have been carrying out foot patrols and guard duties since terrorist attacks in Paris in early 2015.
An investigation was under way which would establish "the motivations and circumstances" of the incident, Parly said.
But Levallois-Perret Mayor Patrick Balkany said that he had no doubt that it was a "deliberate act."
The BMW vehicle was "prepositioned" in an alleyway and drove into the soldiers as they left their barracks to start a patrol, Balkany told broadcaster BFMTV.
Security forces have been repeatedly targeted in individual attacks in France this year.
In April, a policeman was shot dead on the Champs-Elysees by a man with a long criminal record, who investigators determined was acting from terrorist motives.
Failed attacks by individuals have also taken place on police and soldiers on the Champs-Elysees, near the Louvre museum and outside Notre Dame Cathedral.
A man wielding a knife was arrested on Saturday after trying to force his way through a security checkpoint at the Eiffel Tower.
Anti-terrorism prosecutors are also looking into that incident, although the suspect has been sent to a psychiatric hospital where he was previously being treated.