Greek emergency services battled a massive wildfire threatening Athens for a third day Tuesday after thousands spent a night away from their homes.

At least one person has died and 66 people have been treated for injuries, authorities said. Five firefighters have been hurt.

Fuelled by strong winds, the wildfire raced across parched landscape north of the capital, wreaking widespread destruction with dozens of houses, cars and businesses turned into charred shells.

The body of a Moldovan woman was found on Tuesday in a burned-out factory in the suburban town of Halandri.

The Greek government appealed for assistance from other European nations. France, Italy, Czech Republic, Romania, Serbia and Turkey were sending hundreds of firefighters along with helicopters, fire engines and water tankers, authorities said.

The fire has badly hit the suburbs of Nea Penteli, Palaia Penteli, Patima Halandriou and Vrilissia.

"Never in a million years did I think a fire would come here," 65-year-old Sakis Morfis told AFP outside his gutted home in Vrilissia.

"We're without clothes, money, everything was burned inside," he said.

Hundreds of firefighters, backed by around 200 fire engines and 12 water-bombing aircraft battled the blaze that broke out Sunday in Varnavas, some 35 kilometres (22 miles) northeast of Athens, the fire department said.

Costas Tsigkas, head of the association of Greek firefighter officers, told ERT state television the army of firefighters had made progress during the night.

"We are at a better level across the front," Tsigkas told ERT state television.

"But conditions again will not be easy. There will be winds from midday onwards" and "every hour that passes will be more difficult", he said.

Fanned by strong winds, the wildfires grew into a 30km-long front of flames more than 25 metres (80 feet) high in places, according to ERT.

Greece's National Observatory, itself threatened by the wildfire, said Monday that at least 10,000 hectares (24,700 acres) of land had been devastated.

The observatory said temperatures of up to 38 degrees Celsius (100 Fahrenheit) are expected in Athens on Tuesday, with winds of up to 39 kilometres (24 miles) per hour.

'Unanswered questions'

Greece's conservative government came under attack from the press over the fire.

"Enough is enough," thundered the front page of Greece's top-selling centrist daily Ta Nea. The liberal Kathimerini said the "out of control" inferno "had left huge destruction (and) unanswered questions".

"Evacuate Maximou," said the left-wing Efsyn daily, referring to the building housing the prime minister's office.

The blaze scaled Mount Pentelikon, also known as Mount Pentelicus, that overlooks the capital and bore down on suburbs that are home to tens of thousands of residents.

Dozens of evacuation orders were issued and many thousands fled.

Prime Minister Kyriakos Mitsotakis, who was vacationing on his home island of Hania, returned to the capital on Sunday.

He was shown visiting the Civil Protection Ministry on Monday but has yet to comment on the disaster.

The destruction revived memories of the July 2018 fires in Mati, a coastal area near Marathon where 104 people died in a tragedy later blamed on evacuation delays and errors.

The summer wildfire season in Greece this year has seen dozens of daily blazes after the Mediterranean country recorded its warmest winter and the hottest June and July since reliable data collection began in 1960.

Scientists say that human-induced fossil fuel emissions are worsening the length, frequency and intensity of heatwaves across the world.