A large fire destroyed much of a nature reserve at the foot of the Sierra de la Ventana mountains in Argentina, but workers managed to control it Saturday, authorities said.

The blaze ripped through 48,000 hectares (118,610 acres) of a grassland area, including much of he 6,700 hectares of Ernesto Tornquist Provincial Park, in Buenos Aires province.

"After a week of hard work, the fire is now under control," regional fire chief Martin Haag told the Todo Noticias television channel.

"It had extreme characteristics, with high temperatures, drought and winds that rotated and increased in speed."

He explained that the fire increased in magnitude amid a historic heatwave affecting much of the country during its Southern Hemisphere summer.

A total of 35 fire crews, 250 firefighters, 40 navy troops and 25 rangers worked to extinguish the fire, aided by two air tankers and two helicopters, authorities said.

"The priority is definitely to handle this situation and then move to strengthen and recover lost heritage," said Buenos Aires province Governor Daniel Scioli, who flew over the affected area.