Aircraft from France and Spain and helicopters from Germany have joined the battle to fight forest fires in central and northern Portugal.
More than 3,000 firefighters are tackling the blazes which have killed at least 13 people and destroyed around 134,000ha of forest.
Poor land management and the lack of a central registry of land ownership are being blamed for the fires.
Experts said that if there was a central land registry, the authorities could identify forest owners and make them create fire walls or plant fire resistant tree species, making it easier to prevent or control fires.
The problem is exacerbated by the fact that many Portuguese have abandoned land they own in rural areas, leaving no-one to look after it.
The planting of eucalyptus for paper and pulp has also contributed to the fires as the species burns more easily than many others.
