More than 600 firefighters were deployed to fight the blazes on Friday, and several towns were evacuated as police closed roads and highways.
The Spanish government has said it fears more wildfires this year following an unusually dry winter in parts of southern Europe and rising average temperatures due to climate change.
“THEY ARE BURNING OUR ASTURIAS. We are dealing with real terrorists who are endangering lives, towns and cities,” Adrian Barbon, the head of the regional government, said on Twitter.
In Asturias and the neighboring region of Cantabria, dozens of fires have already been extinguished by emergency services in the past two days.
Most of them were set on purpose and fanned by high winds, authorities said.
Police said they have opened multiple inquiries, but no arsonist has yet been identified. Penalties for arson can be up to 20 years in prison, depending on the damage caused.
Andres Perez, a 68-year-old resident of the town of Setienes, told Reuters he was convinced the fires were the result of arson, but did not know who was behind them or what their motives were.
“But what we do know is that it is a total ruin, both for the ecology, material and for everything.”
In the past, deliberate fires have often been associated with ranchers seeking more grazing land for their livestock. Asturias repealed a law in 2017 banning cattle grazing in forest areas damaged by fire.
“These fires are unparalleled and it is devastating to watch with impotence as the fires engulf our country,” Oscar Perez, the mayor of Luarca – a municipality comprising 164 towns and hamlets – told state broadcaster TVE.
The densely forested mountain area is one of the rainiest areas in Spain, although fires are common in March, according to the regional government.
A combination of scant rainfall, high temperatures and winds has placed most of northern Spain at high wildfire risk.
Spain recorded the warmest March 29 on record on Wednesday, with temperatures surpassing normal levels by seven to 14 degrees Celsius, according to the weather agency AEMET.