As Spain enters its third week of heatwave alerts, firefighters continue to battle blazes in the northwest and west of the country, with army units deployed to help contain the blazes.

Spanish Prime Minister Pedro Sanchez said he had held a "coordination meeting" on Saturday, as France and Italy sent water bombers to an air base near Salamanca to help with the firefighting efforts.

"The government continues to work to fight the fire with all the means at its disposal," he said on X.

The most serious forest fires were in the northwest and west of the country, in the regions of Castile and Leon, Galicia, Asturias and Extremadura.

Around 10 roads remain closed across the country, as well as the train line between Madrid and Galicia.

Around 3,500 military from a special emergency unit were deployed around the country, with some political leaders calling for more. (AFP)