The fire, which officials described as "very virulent" and of "exceptional scale", began late afternoon in the sprawling Fontainebleau forest about 60 kilometres (40 miles) south-east of the capital, a onetime royal hunting preserve that today is dotted with quiet villages.It had raced across 300 hectares -- the size of Central Park -- by 11:00 pm (2100 GMT) and was still spreading, officials said, causing the partial closure of the A6 highway, the country's main north-south artery. Around 15 homes had been evacuated in the nearby village of Vaudoue and firefighters were defending several other towns in the area, said the local Seine-et-Marne fire service.Without the firefighting planes, other villages would already have been evacuated, said Olivier Compta, who is overseeing the firefighting operation.Some 400 firefighters and special equipment laboured to contain the flames, which erupted just ahead of the July 14 national holiday and on the first major weekend for departures for the summer holiday season.Traffic was disrupted in places along the highways in the area, as well as along the high-speed rail line leading to the south-east of the country.Eric Brocardi, of France's national federation of firemen, said it was the first time that fire bomber planes had been sent up from the normally drier and hotter south of the country to extinguish fires in the Paris region.Two firefighting helicopters and an observation aircraft were also helping to fight the blaze, he added.Earlier, firemen dealt with a fire that had blocked a highway running east from Paris and disrupted a high-speed train line to the south of France.- Third heatwave - French rail company the SNCF said on Sunday evening there were delays of up to six hours for trains arriving at or leaving from Paris's Gare de Lyon.At the station, 34-year-old physiotherapist Kelly took the delay in stride."It's global warming," she said. "It's the disruption of the seasons...there are political decisions to be taken."Europe has been battered by three heatwaves since May, with temperature records broken in several countries.The Paris region -- and large parts of the rest of France -- is currently experiencing its third heatwave since May, increasing the risk of fires.