ATHENS (AFP) - Hundreds of Greek firefighters fought for a second day on Friday (May 21) to bring a large forest blaze under control, with better weather conditions providing hope that the flames could be subdued.

Nearly 300 firefighters battled throughout the night to keep the fire contained on the Geraneia mountain range, some 90km from Athens.

"Conditions are much better (today)," fire department spokesman Vassilis Vathrakogiannis told Skai TV, adding that the emergency services were "hopeful" that the fire could be contained with the contribution of water bombers.

Civil protection deputy minister Nikos Hardalias told reporters: "We are cautiously optimistic that during the day, with weather conditions gradually improving, we will limit the fire."

It is estimated that over 40 sq km of pine forest and other land is estimated to have been razed already, he said.

Fifteen aircraft were assisting operations on Friday and gale force winds are expected to abate.

Army clearing machinery is supporting efforts, Mr Hardalias said.

The state civil protection agency on Thursday had said hundreds of people had been evacuated from 17 villages and hamlets in the surrounding area, as well as from local monasteries.

"The fire got to within 5km of Megara (on Thursday)," a local resident told Skai, referring to a coastal town around 60km west of Athens.

"Vineyards, cottages, crops have been burned, it's a total disaster... many of my friends have had their homes burned," he said.

Officials acknowledge that a number of properties have been destroyed, but decline to give precise figures before the fire is extinguished.

It started late on Wednesday in the Corinthian Gulf village of Schinos, apparently by someone burning vegetation in an olive grove, the civil protection agency said.

Smoke from the fire choked Athens on Thursday, with ash falling from the sky.

The national observatory in Athens said the smoke had reached the Cycladic islands as far as Ikaria. The Health Ministry recommended that people limit physical activity and close doors and windows.

Wildfires pose a challenge for Greece every year during the dry summer season, with strong winds and temperatures frequently exceeding 30 deg C.

In 2018, 102 people died in the coastal resort of Mati, near Athens, in Greece's worst-ever fire disaster.