In recent days there have been a "high number" of fires, in Soares's words, with one in Cerva parish in the municipality of Ribeira de Pena, in Vila Real district, requiring more than 70 fire fighters to combat it and threatening several homes.

Since the start of this year, according to figures from the GNR, the national guard, there have been several fires that started as a result of bonfires of agricultural waste, some of which have claimed lives.

“These fires have to be analysed case by case," Soares told Lusa. "We can't forget that this year alone there have been more than 2,500 started. It's an incredible thing and so there's a need to reflect, find out what's happening.

"An exaggerated number of mortal victims has also been recorded resulting from bonfires," he added, noting that all these victims have been elderly.

There is a need, Soares stressed, for the authorities to warn people against behaviours that can lead to fires spreading, so as to create a culture of prevention.

One of the causes of the large number of fires in recent days, Soares argued, is the amount of combustible material in forests, following recent heavy rains, and climate change. But changes in land use - such as the fact that plots around rural homes are being cultivated less - may also be factors.

"Something abnormal is happening," he said.

The GNR in January and February recorded 72 crimes of arson in the country's forests, with the detention of 27 people in total. It also started 83 proceedings for administrative offences under the forestry defence system against fires, above all relating to the illegal burning of material.

Last year the GNR recorded 21,952 occurrences relating to forest fires, with 9,864 crimes and 65 people detained for arson in forests. A total of 4,578 people were charged with administrative offences in this regard.

According to the GNR, last year more than 527,000 hectares of forest burned, 367,000 more than in 2016.