French authorities are investigating an 18-year-old volunteer firefighter suspected of starting a significant forest fire that consumed a portion of the historic Fontainebleau forest. The blaze, which began last Sunday, led to partial closures of the country's main north-south motorway.

Prosecutor Diane Ngomsik stated that the suspect initially confessed to setting fire to twigs using a lighter and petrol, but later retracted his statement. A second 18-year-old man has also been placed under formal investigation, a procedural step that could lead to charges and a trial.

President Emmanuel Macron announced that 10% of the forest had been affected by the fire. He acknowledged that fortunately, no one had been killed or injured. The Fontainebleau forest, a UNESCO World Heritage site since 1981, is a significant natural and cultural landmark.

Maron emphasized that there would be no leniency for arsonists, as France, along with other parts of Europe, is grappling with a series of unseasonable heatwaves. This year, France has recorded nearly 11,000 fires since January 1.