By Alison Roberts In Lisbon

The blazes are the biggest to hit the country in over 20 years

Fires responsible for the deaths of at least eight people are continuing to rage across Portugal.

Authorities say the blazes - which have affected 13 of the 18 districts on the Portuguese mainland- are the worst in living memory.

The country has been forced to call in help from abroad.

Sunday was another grim day for Portuguese emergency services and residents in the areas ravaged by forest fires.

Two further deaths were reported during the morning after four on Saturday, which included one fireman.

Portugal's appeals for help have not gone unheeded.

On Sunday, two firefighting planes from Italy and five from Morocco started work, joining the Spanish firefighters that are already on the job.

But although temperatures dropped somewhat from Saturday's 40C, civil defence officials say that did not really help.

Forest fires are a regular occurrence in Portugal in the summer but this year, unusually hot dry air and strong winds have combined to make many unmanageable.

Thousands of acres have been devastated, particularly in the centre where much of Portugal's forests are concentrated.

Officials say it is impossible to estimate how many homes have burned.