BUENOS AIRES, Argentina (AFP)— A fire that destroyed around 600 hectares of a national park in Argentina was the result of arson, an official said Sunday.

“We have confirmed that the fire originated intentionally,” said Ignacio Torres, the governor of Chubut province, who had flown over Los Alerces National Park, a UNESCO World Heritage site, to inspect the destruction.

“Those responsible for starting the fire will have to answer to the courts,” he added, calling for “exemplary measures.”

Torres had alleged in an earlier radio interview that the fire was started by members of the Mapuche Ancestral Resistance (RAM), a marginal Indigenous group which claims land taken by the state during the 19th century and advocates against logging.

“The problem is not Indigenous people but these criminals who take land under false flags… I think it is time to put a definitive stop to it,” he had said.

Firefighters are battling the blaze that has ravaged the park for three days, trying to prevent the flames from reaching the nearby towns of Esquel and Trevelin, about 2,000 kilometres (1,200 miles) southwest of Buenos Aires.

They are being supported by two hydrant planes, an observation aircraft and two water-bombing helicopters, according to official information.

The Chubut governor’s office said the work on Sunday was complicated by weather conditions, which caused smoke to hang over the area and reduce visibility.

Temperatures in Patagonia, a normally cold and windy region in Argentina’s far south, have topped 40 degrees Celsius (104 Fahrenheit) in the southern hemisphere summer, with two provinces declaring states of emergency due to fire risk until April.

Los Alerces Park covers more than 260,000 hectares. Glaciers have shaped the landscape of the region, creating strings of ponds and lakes, hanging valleys and rivers.

It is also home to pristine forests of alerce trees, the second-longest living tree species in the world.