Thousands of hectares of forest have been devoured since Monday in a part of Argentina still recovering a year on from its worst wildfires in three decades.

Hundreds of firefighters with backup from helicopters and six water-bombing planes were working to contain the flames whipped up by high temperatures, strong winds and severe drought conditions.

"We evacuated more than 3,000 tourists" from the Puerto Patriada lake resort, along with a few dozen permanent residents, Ignacio Torres, the governor of Chubut province, said on Wednesday.

He did not say where the visitors were from.

Torres said at least one of the fires was the result of arson, and announced a reward of 50 million pesos (about $33,000) for information on the culprits.

Besides Chubut, fires are also raging in the provinces of Neuquen, Santa Cruz and Rio Negro as well as southern Buenos Aires province, according to the Federal Emergency Agency.

Nearly 32,000 hectares -- an area twice the size of Brussels -- was burnt in Argentine Patagonia in January and February last year, the peak of the Southern Hemisphere summer.