Strong winds caused firestorms in the North of Athens on Friday, and also sparked further wildfires, Greek state television reported.
Several warehouses and industrial plants along the motorway between Athens and northern Thessaloniki caught fire, and there were many explosions.
The government called on the residents of Malakasa and Sfendali to leave the area in warnings sent by text message.
Members of the security forces moved from house to house to make sure no one was left behind.
Further evacuations were announced for Oropos, a town further north some 25 kilometres from Athens.
In the past 24 hours, 86 new forest fires had started burning across the country, the Greek fire brigade tweeted in the morning.
Huge clouds of yellow smoke were visible even dozens of kilometres from the flames and there was a smell of burning, and ash rained down in many areas.
At least 18 people were injured and were hospitalised, with most suffering from respiratory problems, Health Minister Vassilis Kikilias told state television on Friday.
A leading medic warned of the dangers of air pollution.
“Do not go out of the house,’’ said Nina Gaga, who heads the pneumology clinic at Athens’ Sotiria hospital.
She said regular protective face masks that people were using during the pandemic would not help.
Anyone who goes outside should wear a P95 mask or one with an even higher level of protection, she said.
Fires also continue to burn on the island of Euboea and in the Peloponnese, with several out of control.
On Euboea, the inhabitants of the village of Agia Anna in the north-east of the island had to be brought to safety by boat.
Fires were also burning in the north-west, where villages have also been evacuated.
The nation must now focus on stopping the fires from spreading, Greek news agency ANA reported.
Given the strong winds, there was no chance that they can be brought under control for now.
“We are dealing with dozens of forest fires. Three of them in Athens, the Peloponnese and Euboea are of huge proportions,’’ Prime Minister Kyriakos Mitsotakis told state television on Thursday night.
He warned of an “unprecedented situation because the past few days of heat and drought have turned the country into a powder keg’’.
People were banned from going to forests at least until Monday, and any activities that could lead to sparks or flames were also prohibited.
