The battle by firefighters in France to bring under control a large wildfire raging in forests south of the country's capital is entering its second day.

The Fontainebleau forest blaze, described by officials as "virulent" and of "exceptional scale", partially closed the country's main north-south highway.

Interior minister Laurent Nunez has indicated the blaze may have been deliberately set, after officials said the fire had raced across 800 hectares in the forest about 40 miles (60km) south-east of Paris.

On Monday, Nunez said that two people had been arrested in connection with the Fontainbleau blaze, and 59 across the country in connection with fires.

The Paris region is suffering through its third heatwave this year during a summer in which temperature records have been broken in several countries across Europe.

It is the first time firefighting planes had been sent up from the normally drier and hotter south of the country to tackle fires in the Paris region, Eric Brocardi, of France's national federation of firefighters, said.

Two firefighting helicopters and an observation aircraft had also been deployed, he added, according to French news agency Agence France-Presse.

"The aim is to save lives and property," he was quoted as saying.

Nunez suggested on Monday that authorities are exploring the possibility that the fire was started intentionally.

"There were about 10 fire ignition points within a perimeter of 1,000 meters, which suggests that it could have been deliberately set," he said in a statement reported by the AFP news agency.

Nunez told France 2's 8 PM News that two people were arrested for "deliberate or accidental arson" in the region.

Meanwhile, French President Emmanuel Macron wrote that the Fontainebleau forest had been "struck by a fire of exceptional magnitude".

"All available resources are being mobilised," he wrote on social media, as he expressed "solidarity" with local residents and praised firefighters tackling the blaze.

Earlier, a fire had also blocked a highway running east from Paris and disrupted a high-speed train line to the south of France.

Travellers were facing delays of up to six hours for trains arriving at or leaving from Paris's Gare de Lyon, French rail company SNCF said on Sunday evening.

Julien Marion, director general of civil security in France said on Friday that since the start of this year, wildfires have covered some 25,000 hectares of land in France.

The latest French heatwave has forced the temporary shutdown of three nuclear power stations to avoid the discharge of warm cooling water into overheated waterways.

Organisers of the Tour de France cycling race also shortened Sunday's stage by 30km (19 miles) as temperatures neared 40C.

Climate change is driving up temperatures around the world, and Europe is the fastest warming continent, heating up twice as fast as the global average, according to the Copernicus climate service.

This is causing increased summer heatwaves, greater pressure on Europe's water supply, and more intense wildfires.

The record-breaking temperatures across Europe this summer have led to major wildfires, most notably in Spain where at least 13 people were killed by Thursday's wildfire in Almeria, one of the country's deadliest ever.

And in the UK, a large wildfire in north Wales was declared a major incident by emergency services on Sunday, as firefighters tackled fires across England and Wales.