Greece/Athens: A fast-moving wildfire fuelled by gale-force winds spread to the edge of Athens on Monday, torching trees, houses and cars and forcing evacuations of several hospitals and a dozen towns and villages, Greek authorities said.

Hundreds of wildfires have broken out across Greece since May. While summer fires are common in Greece, extraordinarily hot and dry weather linked to climate change has made blazes more frequent and intense. Wildfires fanned by extreme heat have also raged this month in parts of Spain and the Balkans.

More than 670 firefighters backed by volunteers, 183 fire engines, 32 waterbombing planes and helicopters battled the latest wildfire that broke out at 3 pm (midday GMT) on Sunday near Varnavas 35 km (20 miles) north of the capital.

By Monday the conflagration, the worst in Greece this year, had advanced to the village of Grammatiko, the seaside municipality of Nea Makri and the fringes of Athens' densely populated northern suburbs at the heavily wooded Mount Penteli.

"It hurts, we have grown up in this forest. We feel great sadness and anger," 24-year-old Penteli resident Marina Kalogerakou told Reuters outside her home, which the flames had nearly reached.

Strong winds were constantly changing the direction of the fire and the extent of the area engulfed by flames was estimated at 30 km (18.64 miles).

Winds were expected to pick up further in the coming hours, aggravating the blaze, said Theodore Giannaros, a researcher at the National Observatory of Athens. "We have a very difficult day ahead of us," he told state TV ERT.

Firefighting aircraft resumed operations early on Monday after an overnight pause. Police said they had helped evacuate at least 250 people in danger. Some residents spent the night in shelters but authorities could not yet provide an exact number.

At least three hospitals and several communities had been evacuated in the Penteli area.

The blaze, with flames as high as 25 metres (82 feet), had spread "like lightning" due to gale-force winds, fire brigade spokesperson Vassilis Vathrakogiannis said on Sunday.

Thick clouds of smoke darkened the sky over Athens by Sunday evening. Hours later, the flames were nearing the residential suburb of Dionysos about 23 km (14 miles) northeast of the city centre, and nearby districts.

Prime Minister Kyriakos Mitsotakis visited the fire brigade's operations centre on Monday morning after rushing back from a holiday break on the island of Crete - with memories still fresh of a 2018 fire that killed 104 people in the seaside town of Mati, near the capital.

After its warmest winter on record and long periods of little or no rainfall, Greece is forecast to record its hottest-ever summer. It is on high fire alert at least until Thursday with temperatures forecast at up to 40 Celsius (104 Fahrenheit).

"Unfortunately the forecasts...were confirmed," Climate Crisis and Civil Protection Minister Vassilis Kikilias said in a televised statement. The state's response was immediate, he said, and the first aircraft were operating five minutes after the wildfire broke out.