Portuguese police have arrested 14 suspected arsonists this week, who may have set some of the dozens of deadly wildfires raging across the country, contributing to the fire risks stemming from climate change and rural depopulation.

More than 100 wildfires are stretching thousands of firefighters to the limit in northern Portugal. The country’s worst spate of fires in recent years is blamed for seven deaths since they spread out of control over the weekend.

At least seven people have died after wildfires in the Aveiro and Viseu areas of Portugal, although cooler weather has helped tackle the flames. Dozens of homes have been destroyed and tens of thousands of hectares of forest and scrubland have been lost to the flames.