Hundreds of firefighters were battling to control two massive wildfires in Greece on Wednesday, one raging for nine straight days, that have left hundreds homeless and caused incalculable damage.

With the assistance of a huge multinational force, Greek fire crews were fighting to beat back blazes on the island of Evia and in the Peloponnese peninsula in rugged terrain.

Hundreds have been left homeless and face a harsh winter, not only at the mercy of floods, but also because of their lost agricultural livelihood and income from tourism.

"I think we can say that the fire fronts are slowly coming under control," Yiannis Kontzias, mayor of the Evia town of Istiaia that has been under threat for days, told state TV ERT.

"Yesterday, we saw the light of the sun for the first time in days," he said, referring to giant smoke clouds that have choked residents and obstructed flights by water-bombing aircraft.

'We face extinction'

But even as the immediate danger receded, Kontzias said local businesses "face extinction" in coming months in a tourism season already decimated by the Covid-19 pandemic.

"We have lost the month of August, which would have sustained people here over the coming year."

"(Local) tourism has been demolished, most (visitors) have left," he said.

"The damage is huge, and the environmental disaster will have economic repercussions for decades," he said.

Aidipsos, one of Greece's main spa towns, would normally have tens of thousands mainly Greek and Balkan visitors in August and revenue of around 15 million euros ($17.5 million), local operators say.

But local hoteliers president Theodoros Roumeliotis says August reservations have collapsed by 90 percent.

"It's a colossal loss," Roumeliotis told AFP.

"Right now, hotels are obliged to refund one million euros in reservations cancelled," he said, adding that some operators were unlikely to survive the blow.

The fire situation was more precarious on Wednesday in the mountainous Peloponnese region of Gortynia, home to dense forests and deep ravines.

Christos Lambropoulos, deputy governor for the broader Arcadia region, said efforts were concentrated on keeping the fire from reaching the thickly forested Mount Mainalo.

"Villages do not seem at risk at the moment... but conditions change by the hour," he told ERT.

Three people have died in the latest fire wave, which came in the midst of Greece's most severe heatwave in decades.

Several firefighters have been hurt, some critically.

Many here admit that help from abroad has been critical in averting an even greater disaster.

EU states and other countries have so far contributed 21 aircraft, 250 vehicles and more than 1,200 firefighters, some of whom were due to arrive by Friday.

Forces in Gortynia were beefed up Wednesday to nearly 600 firefighters including crews from the Czech Republic, Britain, France and Germany.

Another 60 firemen were tackling a smaller fire in Laconia, in the southeastern Peloponnese, the fire department said.

In Evia, a presence of nearly 900 firefighters was arrayed against the wildfires including Cypriots, Moldovans, Poles, Serbs, Slovaks, Romanians and Ukrainians. Serbian, Swedish and Swiss planes and helicopters were among a fleet of seven aircraft providing support.

Call for resignations

There have been growing calls in Greece for the resignation of top public safety officials who as recently as June had insisted that the country was well-prepared.

There was additional anger over the loss last week of much of the forest of Varibobi, one of Athens' last remaining nature reserves. Olympia, home to the ancient Olympics, also narrowly escaped destruction earlier this month.

"(Our resources were) stronger than ever before. We faced an operationally unique situation with 586 fires in eight days during the worst weather phenomenon in 40 years," civil protection deputy minister Nikos Hardalias insisted on Tuesday.

Greek Prime Minister Kyriakos Mitsotakis this week apologised to the nation for any possible "shortcomings" in the state's response. He is to hold a press conference on Thursday as pressure mounts for heads to roll.