Train services linking Athens with the Peloponnese have also been cancelled following the fires.
The severely burnt bodies were entwined in groups in "a final attempt to protect themselves", said rescuer Vassilis Andriopoulos. But some suggested that the sheer force of winds, thick pine, fire and panic was a deadly combination making even the most well-executed evacuation plan futile.
Image: More than 100 people are being treated in hospital. Eleven of the adults were in serious condition. "We're talking about a biblical catastrophe in this wonderful area of Mati", he said. Three of the cases are considered life-threatening.
"It is a hard night for Greece", said Prime Minister Alexis Tsipras, looking pale after returning from a visit to Bosnia.
Some 187 people have been hospitalised, with 82 being treated on Tuesday evening, including nearly a dozen children, most of whom were in a "serious condition", the fire services said.
Twenty-six of the dead were found at first light Tuesday huddled together in one compound near the sea in the community of Mati, near the port of Rafina.
How many people are missing?
The Ministry of infrastructure and transport reported that in the affected regions, more than 200 houses were completely destroyed by fire, 234 houses badly damaged and in need of fix.
Wildfires sweeping through a Greek resort town have killed at least 74 people including families with children found clasped in a last embrace as they tried to flee the flames. The blaze broke out Monday afternoon during a hot, dry spell but the cause was not immediately clear.
More than 280 firefighters were still in the area to the northeast of Athens, dousing the remaining flames to prevent flare-ups.
Embassy Chargé d'Affaires Rosario Lemque reported that there were no Filipinos among the casualties in the deadly blaze.
"The 44th anniversary of the restoration of democracy in Greece is overshadowed by this tragedy", Greek President Prokopis Pavlopoulos said, according to Greek national news agency AMNA. Associated Press writer Costas Kantouris in Thessaloniki contributed.
Authorities said they would use an unmanned drone from the United States to monitor and track any suspicious activity.
Some people swam out hoping that boats would come to their rescue.
Two major forest fires are raging out of control on either side of the Greek capital Monday, burning houses, prompting residents to flee and turning the sky over Athens a hazy orange from the smoke. Some people were reported to be trapped on a beach by the flames.
Greece has requested firefighting help from the European Union, and Ms Malliri said a military transport plane is arriving with 60 firefighters from Cyprus, while two water-dropping planes are expected from Spain. Local authorities said they were evacuating children's summer camps, while dozens of homes and cars were destroyed.