Flames swept through a town near Athens overnight and hundreds of people were evacuated by ferry from the island of Evia as wildfires burned across Greece for a fifth day on Saturday.

On Evia, east of the capital, a fire which began on Tuesday quickly burgeoned into several fronts, ripping through thousands of hectares (acres) of pristine forest across the northern part of the island and forcing the evacuation of dozens of villages.

More than 400 wildfires broke out in the last 24 hours, with the biggest fronts still burning in Evia, the second-biggest Greek island, and areas in the Peloponnese including Ancient Olympia, the site of the first Olympic Games.

Prime Minister Kyriakos Mitsotakis called it a "nightmarish summer", adding the government's priority "has been, first and foremost, to protect human lives".

The fire on Mount Parnitha on the outskirts of Athens, which forced the evacuation of thousands of people since late Thursday, had receded by Saturday afternoon but winds were forecast to strengthen, meaning there was still a high threat they would flare again.

"Under no circumstances can we be complacent," Deputy Civil Protection Minister Nikos Hardalias said during an emergency briefing. "We are fighting a very big battle."

Wildfires have erupted in many parts of the country amid Greece's worst heatwave in more than 30 years, tearing through swathes of forestland, destroying homes and businesses and killing animals.

On Friday night, strong winds pushed the fire into the town of Thrakomakedones north of Athens, where it burned homes. Residents had been ordered to evacuate and there were no immediate reports of casualties.

The blaze left behind burnt and blackened houses and cars among scorched pine trees. A cloud of smoke hovered over the capital.

"(It's) really bad," said Thanasis Kaloudis, a resident of Thrakomakedones. "All of Greece has burned."

Neighbouring Turkey is also battling what President Tayyip Erdogan says are the worst wildfires in its history and five fires were still burning there on Saturday.

That number was slightly lower than in recent days. In the Mediterranean resort of Manavgat, where the first fires broke out 10 days ago, rain showers helped firefighters to extinguish the last flames.

Further west in the Aegean province of Mugla, four fires were still blazing as a sustained, dry heatwave continued, while another fire burned inland in Isparta.

Eight people have died in fires that have ravaged Turkey's southwestern coastal regions, burning tens of thousands of hectares and forcing thousands of residents and tourists to leave homes and hotels.

Escape By Ferry

Greece has received reinforcements from Cyprus, France and Israel to fight the blaze near Athens, assisted by the army and water-bombing aircraft. Germany is sending 216 firefighters and 44 vehicles expected to arrive in three to four days, the Federal Office of Civil Protection and Disaster Assistance tweeted on Saturday.

Hundreds of people, including many elderly residents, were evacuated by ferry late on Friday from the town of Limni as the sky turned an apocalyptic red.

One man died in Athens on Friday after being injured by electricity pylon and at least nine others have been injured, authorities said.

The government planned to reimburse people affected by the fires and would designate the burned land as areas for reforestation, Mitsotakis said.

Residents in suburbs north of Athens have been forced to leave in a hurry with the few belongings they can take.

"Our business, our home, all of our property is there. I hope they don't burn," Yorgos Papaioannou, 26, said on Friday, sitting in a parking lot with his girlfriend as ash fell around them from the smoke-filled sky.