A wildfire that reached the northwestern outskirts of France's second-biggest city of Marseille was under control on Wednesday, but not over, officials said, warning that it could flare up again.

A wildfire spurred by hot summer winds reached France's second-largest city on Tuesday, grounding all flights to and from Marseille, injuring at least nine people and forcing many residents to evacuate or barricade themselves indoors as smoke choked the Mediterranean air.

A wildfire that had reached the northwestern outskirts of France's second city of Marseille lost intensity overnight on Wednesday, but the airport was closed as firefighters continued to battle the flames.