A driver with no previous record of radicalisation on Wednesday "deliberately" mowed down five people on the French Atlantic island of Oleron, seriously injuring two of them, a minister said, in a lower toll than previously reported.

The suspect was a 35-year-old fisherman from the island who lived alone, local officials and a prosecutor said.

The man on Wednesday morning aimed his car at pedestrians and cyclists along a path on the scenic island off the western city of La Rochelle, Interior Minister Laurent Nunez said.

He ran over five people in 35 minutes, gravely wounding two, including a 22-year-old woman, he said.

The man was, however, "not known to intelligence services as having been radicalised," he added, urging the public against jumping to conclusions, and saying there was no reason to involve any anti-terror prosecutors in the probe at this stage.

Prosecutor Arnaud Laraize said earlier that the suspect was an Oleron resident and initially reported that 10 people had been injured.

Laraize said the man – already known to the police for alleged involvement in petty crimes – cried "God is the greatest" in Arabic when arrested.

The expression is a key refrain in Islam, but also used by militants carrying out attacks.

Police used a taser to arrest the suspect as he set fire to his car, Nunez said.

The prosecutor said the man ran over people on a road between Dolus d'Oleron and Saint-Pierre d'Oleron.

The mayor of Saint-Pierre d'Oleron told local journalists the man lived in a mobile home in his town and was "someone who lived alone, had a very isolated life."

A lawmaker from the anti-immigration National Rally (RN) party said the woman who was gravely wounded was his aide and had been out for a morning jog.

RN vice-president Sebastien Chenu, leaping to conclusions about the nature of the attack, earlier in parliament warned of "the Islamist threat on our country." (AFP)