Some 10,000 ha (24,700 acres) of land has been charred by fire

On a visit to the stricken Galicia region, Mr Zapatero said some 1,200 army personnel would be deployed to help firefighters.

Three people have died in the fires that have been raging since last week.

Fourteen suspects have been arrested, amid claims by the authorities that many blazes were started deliberately.

"The interior minister will be here tomorrow, keeping an eye on things, and then other members of government will come to Galicia," Mr Zapatero said in the regional capital Santiago de Compostela.

Galicia's fires forced the evacuation of some residents See the forest fires

He also blamed arsonists, saying that "so many fires cannot simply be the fruit of unfavourable [weather] conditions, there are unquestionably criminal actions".

On Wednesday, some 1,000 people held a rally in Santiago, protesting against what they called "fire terrorism", the AFP news agency reported.

Mr Zapatero cut short his holidays in the Canary Islands to visit the affected area.

But he was booed by some members of the public who said he had been too slow to respond to the emergency.

'Unprecedented destruction'

On Thursday, thousands of firefighters - helped by fire-fighting planes - were still trying to put out more than 100 fires in the woodlands.

But high winds and dry weather conditions were fanning the blazes, officials said.

Although Galicia suffers from forest fires every year, this year's destruction has been described as "unprecedented" by local officials, AFP reports.