NOISY-SUR-ECOLE, France (AFP) — French President Emmanuel Macron on Thursday pledged “zero tolerance” for arson after wildfires scorched thousands of hectares in France, including in a historic forest near Paris.

Dozens of people have been arrested across the country for starting fires deliberately or by accident as France has sweltered through multiple intense heatwaves since May that have fuelled dry conditions.

Around 35,000 hectares (nearly 86,500 acres) have been impacted by fires — more than during the entire 2025 fire season, according to authorities.

France “has never faced so many outbreaks of fire across the country since the end of World War II”, Macron said during a visit to the Fontainebleau forest near Paris that has seen more than 2,000 hectares hit by fires since July 5.

“Here, as everywhere else in France, there will be zero tolerance” for arsonists “because it is, of course, our national territory that is under attack every time a fire breaks out”, Macron added.

Around 1,000 residents were forced to leave their homes as the fires spread in the forest some 60 kilometres (40 miles) southeast of Paris, in a rare blaze in the north of the country.

Several people have been detained in connection with the incident.

Sparks from machinery used for repair work on the main A6 motorway from the capital to the southeast bordering the forest are believed to have sparked the wildfire.

The head of the construction company and two workers are to be brought before an investigating judge on suspicion of involuntary destruction by fire through a breach of safety obligations.

On Wednesday, two 18-year-old men, one of them a volunteer firefighter, suspected of deliberately starting fires in two other locations in the area, were placed under formal investigation and remanded in custody.

Macron announced a funding drive to raise money to rehabilitate and protect the forest, a UNESCO biosphere reserve.