ATHENS, GREECE -- A major wildfire raged across the northern suburbs of Athens on Monday, triggering multiple evacuations as swirling winds hampered the efforts of hundreds of firefighters and dozens of water-dropping planes.

The blaze started Sunday near Lake Marathon, about 35 kilometres (22 miles) northeast of Athens, coursed across Mount Pendeli and reached the capital’s northern suburbs. It burnt several homes and businesses in the city suburbs and in communities near the lake.

Greece went on high alert but by late night Monday, a drop in winds offered hope and officials reported progress against the massive, fast-moving blaze that spawned flames over 25 metres (80 feet) high.

Fire Department spokesperson Col. Vassileios Vathrakogiannis said firefighters were longer battling a single front but “many active localized blazes," mostly around Marathon and Pendeli.

The Marathon area was the site of a famous battle between Greeks and Persians in 490 B.C. and hosts a museum and archaeological site, but there were no immediate reports of damage from the blaze to either.

Greek firefighters were to be boosted by forces from other countries as early as Tuesday, after Athens sought international assistance, activating Europe’s mutual civil protection mechanism.

A blanket of smoke and ash shrouded central Athens while power cuts hit parts of the Greek capital and affected traffic lights at major central junctions.

Authorities said at least 18 people were injured, mostly due to smoke inhalation as the blaze reached outlying sections of a suburb. Greece’s National Observatory said late Monday that satellite images show the blaze has affected about 10,000 hectares (25,000 acres).

France would provide a helicopter and 200 firefighters with 28 fire trucks, Italy two water-dropping planes and the Czech Republic 75 firefighters and 25 vehicles, officials said, while Serbia and Romania were also readying aid. Neighbouring Turkey's Foreign Ministry said it would dispatch two firefighting planes and a helicopter, while Spain was also finalizing reinforcements to send to Greece.

Firefighters in Greece

The wildfire raced through pine forests left tinder-dry by repeated heat waves this summer. June and July were the hottest months ever recorded in Greece, which also recorded its warmest winter ever. An early start of the fire season this year has strained Greece's firefighting force.

“Firefighters have been working at full tilt for months,” said Nikos Lavranos, head of Greece's main firefighters' union. “They are exhausted.”

Climate Crisis and Civil Protection Minister Vassilis Kikilias said earlier Monday it was “an exceptionally dangerous fire, which we have been fighting for more than 20 hours under dramatic circumstances.” Some areas burning on Mount Pendeli were particularly hard to reach, he added.

Three hospitals, including a children's hospital, two monasteries and a children’s home were evacuated on Monday afternoon. Cellphones in the area got at least 30 push alerts warning people to flee.

“The wind would go in one direction and then in the other," said Spyros Gorilas, a resident of the area of Dioni who hosed down his house with water to save it from the flames. "The smoke was suffocating. You couldn’t see. Your eyes teared up. You couldn’t breathe."

Volunteer in Greece

"Even the helicopter that dropped water, you couldn’t see it," he added. "You could only hear it.”

More than 700 firefighters, backed by 27 special wildfire teams, and armed forces personnel were battling the flames, with 190 vehicles, 17 water-dropping planes and 16 helicopters.

Three Athens hospitals were on heightened alert, while paramedics and ambulances treated five firefighters for light burns and breathing problems, and at least 13 civilians. The Athens Medical Association warned those with chronic conditions, the elderly, pregnant women, children and those with respiratory and heart problems to be extra cautious.

Greece's coast guard diverted all ferries from a nearby port serving several Aegean Sea islands, to another harbour. Sports halls and hotels were turned into evacuation centers.

The police said 380 police officers assisted in evacuations, and helped move more than 250 people away from the path of the flames. It posted a video on social media showing officers carrying elderly people out of their homes to waiting vehicles against the backdrop of a flame-red nighttime sky.

Authorities said some people who refused to leave their homes later became trapped and required rescuing, endangering the lives of firefighters. The affected areas — at the closest, some 15 kilometers (9 miles) from the heart of Athens where the famed Acropolis and other archeological sites are located — typically have thousands of residents.

However, it was unclear how many were away on vacation at the height of the summer season, and how many had obeyed the evacuation orders or stayed on their own to fight the blaze.

Meteorologists warned of the increased danger of wildfires because of weather conditions from Sunday until Thursday. Dozens of other wildfires also broke out in several parts of Greece on Monday.

Wildfires are frequent in the Mediterranean country during its hot, dry summers, but authorities have said climate change is fueling bigger and more frequent blazes.

In 2018, a massive fire swept through the seaside town of Mati, east of Athens, trapping people in their homes and on the roads as they tried to flee in their cars. More than 100 people died, including some who drowned trying to swim away from the flames.

Last year, wildfires in Greece killed more than 20 people, including 18 migrants who became trapped by the flames as they trekked through a forest in northeastern Greece and were caught by a massive blaze that burned for more than two weeks.

Wildfires on Monday also hit neighboring North Macedonia and Albania, which have had high summer temperatures and strong winds.

Associated Press journalists Lefteris Pitarakis in Dioni, Greece; Derek Gatopoulos in Athens, Greece; and Elise Morton in London contributed to this report.