“The minister of internal administration, Eduardo Cabrita, has decided the extension of the provisions, including aircraft, human resources and watch-towers,” the ministry said in a statemeNt.

The extension, the statement specified, covers the 17 aircraft - 13 light helicopters and four medium seaplanes - that have been added to the fire-fighting force in the last week, and the 12 taken on for the period from 16 to 31 October - eight medium helicopters, two heavy seaplanes and two medium seaplanes.

The statement said that the period of operation of the 72 national guard watch-towers is also to be extended to 15 November.

In all 6,957 men and women - including 3,100 fire fighters - are to be on active duty for the purpose, as well as what the ministry described as “overt patrolling on the ground” on the part of members of armed forces, in a bid to discourage arsonists.

The extension comes after the ‘Delta’ phase of fire prevention and combat, which began on 1 October, was to end on Tuesday, with the ‘Echo’ phase starting on Wednesday originally to have seen a reduction of forces on the ground.

The latest official figures show that so far this year fires have consumed more than 418,000 hectares, with more than half of that taking place in the first half of October. According to official data, this makes this year the second worst, after 2003, when 425,839 hectares burned.

This year's fires have claimed more than 100 lives, 64 of them on 17 June in one big fire in Pedrógão Grande, central Portugal, and 45 in the fires that started on 15 October across that region.