Firefighters stretched to the limit as wildfires rage out of control in Portugal

Northern Portugal has been hit by wildfires (Bruno Fonseca/AP)

More than 100 wildfires in northern Portugal are stretching thousands of firefighters to the limit, with seven deaths since the worst spate of fires in recent years spread out of control over the weekend.

Portuguese Prime Minister Luis Montenegro declared a “state of calamity” for the hardest-hit areas on Tuesday, invoking powers to mobilise more firefighters and civil servants.