A woman has been killed and a man injured after a van crashed into two bus stops in different areas of Marseille.
The woman was killed at the second bus stop, while the man was injured in the crash at the first.
The two bus stops are around three miles apart.
The 35-year-old suspected driver was arrested in the scenic Old Port neighbourhood.
Marseille police have said terrorism was not a motive.
A French official said the man, who has not been named, is being treated for psychological problems and is from the Grenoble region in eastern France.
French media reported that a witness noted the van's number plate and gave it to the police, allowing them to make the arrest.
It is not yet known if it was an accident or a deliberate act.
Police in the city told people to avoid the Old Port area and the Boulevard Charles Livon.
Marseille is France's second biggest city.