A firefighter reacts as a house burns during a wildfire in Kineta, near Athens.
The Attica region, which has a population of around 3.5 million people, is home to the Greek capital Athens, the port of Piraeus and a number of suburban towns.
The fires forced Prime Minster Alexis Tsipras to fly back early from a state visit to Bosnia. He has urged citizens to forget their property and focus on survival.
"Everyone should keep their temper and take care to protect the most precious good that is human life," he said.
Greeks skies are reddened above a road block on the road to Kineta, near Athens.
"Property, all that has a material value, (can be) recreated. Human lives are the ones that cannot come back."
Mati resident Nana Laganou, told journalists that she had escaped by running into the sea, and that the fire was "lightning fast" and the "first time" she'd encountered something like this.
"I would have liked to see some (reaction) from the state, but we didn't and we won't and that makes me angry."
Another Mati resident, Kostas Laganos said that he had also escaped the flames by diving into the ocean. "Thankfully the sea was there and we went into the sea, because the flames were chasing us all the way to the water, it burned our backs and we dove into the water," he said.
"It reminded me of the eruption (of Vesuvius in 79 AD) at Pompeii, exactly that, and I said my God, we must run to save ourselves, and nothing else. Terrible."
So far Spain and Cyprus have offered assistance, and Greece has called on other fellow EU members to help battle the blaze.
Various governments, including the US and the Netherlands, offered sympathy to the beleaguered region.