France, July 23 -- The evacuation measures have affected six campsites and a naturist residential estate north of Cap Ferret, a heavily visited area during the summer.

The fire has been burning since Wednesday near the Arcachon basin and has now spread across some 2,000 hectares.

No casualties have been reported so far, authorities said.

"We have a very dense concentration of closely spaced pines, typical of the Landes de Gascogne massif," Captain Wilfried Schneider told French news agency AFP on Wednesday, describing the blaze as one of "rare" intensity.

According to the mayor of Le Porge, Martial Zaninetti, the fire may have been sparked by a cleaning machine on a forest track, but this has not been confirmed by local authorities. C...