Chirac, speaking on the sidelines of the opening day of the 14-nation Pacific Forum in Polynesia, said authorities in France were hunting those responsible with "extreme rigour."

Investigators had been given "draconian instructions" to find the arsonists, said Chirac, saying those responsible will face "punishment of exceptional severity."

Chirac's comments came as firefighters discovered the body of a fourth victim of the blazes, which have roared through densely forested in the Maures region of southeastern France.

On Monday the body of two elderly hikers from Britain were discovered in woods outside the village of La Garde Freinet. The body of a woman was found burned in outside Sainte Maxime, near the trendy resort of Saint Tropez.

Over a dozen fires raged Monday in the Var region between the cities of Marseille and Nice, destroying more than 8,000 hectares (19,800 acres) of woodland, 7,500 hectares alone in the Maures mountains, rescue services said.

TERRA.WIRE