The European Commission is deploying firefighting aircraft to Spain, where at least seven have died as 14 wildfires have flared amid a European heat wave.

Spain's worst wave of wildfires on record spread to the southern slopes of the Picos de Europa mountains on Monday and prompted authorities to close part of the popular Camino de Santiago pilgrimage route.

Defence minister attributes fires to climate change, heat wave. The Interior ministry said 27 people have been arrested and 92 were under investigation for suspected arson since June.

Spain's weather agency warned the public on Monday to be "cautious" of the "very high or extreme fire danger."

This year is turning into one of the worst fire seasons in recent memory in Europe. Firefighters are struggling to contain out-of-control wildfires in western Spain and Portugal.

Europe’s next heat wave is already building over the Iberian peninsula, potentially testing more temperature records after an unseasonably cool start to August.

Spain on Friday warned of "very high or extreme fire danger in most of the country," as firefighters there continue battling 14 blazes in temperatures up to 104 degrees Fahrenheit.

Firefighters have spent days battling blazes in Greece, Portugal, Spain and elsewhere. Forecasters said temperatures could pass 111 degrees in some places on Thursday.

Spain has been hit by a heatwave with the mercury hitting 32C in Seville this week and highs of 35C in Madrid and 31C in Barcelona. The UK has also been issued a yellow heat health warning