Two people have been killed and six areas put on high alert as uncontrolled wildfires spread across Greece.
Huge clouds of smoke are billowing over the northern outskirts of Athens, where people are being urged to leave their homes.
A 38-year-old volunteer firefighter was killed by a falling electricity pole in a suburb of the capital.
Greece’s prime minister says a heat wave has turned the country into a power keg.
Firefighters are battling 154 wildfires across the country.
Fanned by unpredictable winds, the worst blazes are around the north of Athens. Fires are also raging on the nearby island of Evia, and areas close to ancient Olympia, the birthplace of the Olympic Games.
“We are facing another, more difficult night,” said government minister Nikos Hardalias.
“Wildfires of unprecedented intensity and spread, all our forces are fighting the battle day and night to save lives, together with volunteers.”
Thousands of people have been ordered to leave their homes outside Athens as the blaze tore through homes, cars and businesses.
The firefighter was among the first two people killed by the fires.
The other victim was the president of the Athens Chamber of Commerce, Konstantinos Michalos. He was found unconscious in a factory close to where a fire was raging.
A further 20 people have been injured.
Hundreds of residents and tourists on Evia island have been evacuated aboard ferries and fishing boats, as wildfires closed in on its shores.
“We’re talking about the apocalypse, I don’t know how to describe it,” Sotiris Danikas, a coastguard official on the island, told broadcaster ERT.
Greece, like many parts of Europe, has been grappling with extreme weather this summer. A week-long heat wave has sparked wildfires in many parts of the country.
In neighbouring Turkey, authorities are battling the country’s worst-ever wildfires. Six more neighbourhoods near a power station were evacuated on Friday.
Eight people have been killed and tens of thousands evacuated along Turkey’s southern coast.
Greek Prime Minister Kyriakos Mitsotakis says the fires show “the reality of climate change”. Temperatures in the country have been above 40C (107 degrees Fahrenheit) all week.
Hundreds of firefighters and nearly 20 water-bombing aircrafts are trying to control the blazes across Greece. Extra firefighters and planes are being sent in from countries including France and the US.
In the village Krioneri, close to Athens, the fire scorched homes, businesses and factories.
“The fire is uncontrollable,” resident Vassiliki Papapanagiotis told AFP news agency.
“I don’t want to leave, my whole life is here.”