A man rammed a vehicle into three Chinese students near the French city of Toulouse today, leaving one of them in a serious condition, police sources said.
The driver, who was arrested immediately afterwards in the city's Blagnac suburb, acted "deliberately" but was not on a list of known extremists, one source said, asking not to be named.
France has been victim of a series of vehicle attacks by extremists inspired by the so-called Islamic State group, but there was no immediate confirmation of the driver's identity or motive.
The BFM news channel said the man was known to police for previous non-terror crimes and officers were checking reports he suffered from major psychological problems.
All three of today's victims were in their 20s, with a 23-year-old woman the most seriously injured and two men aged 22 and 23 also hurt.
In July last year, a Tunisian man ploughed a 19-tonne truck into a crowd in the southern city of Nice, killing 86 people.