Thousands of residents have been forced to evacuate their homes as wildfires fuelled by soaring heat and strong winds were sparked north of Athens.
One person has reportedly died after the blaze started on Sunday near the village of Varnavas, about 25 miles north of there Greek capital.
More than 685 firefighters and 190 fire engines were battling the flames, which reached up to 25 metres high (82ft) as fires broke out in 40 different locations on Monday.
More: Operators provide warnings over Kos wildfires and thunderstorm disruption
Wildfires force evacuation of Jasper National Park
Jet2 said in an update on its website: “We are aware of the wildfires affecting an area of Athens and are monitoring the situation closely.
“As it currently stands, Athens airport is still open and we are planning to operate our flights as planned. Please allow extra time for you journey to the airport, as there may be road closures in place.”
EasyJet holidays said: “We’re closely monitoring the situation in the Marathon area of Athens, and are working with our partners in destination. We’d like to remind our customers currently in the area to continue following the guidance of their hotel and the local authorities.”
Greek prime minister Kyriakos Mitsotakis cut short his summer holidays to oversee emergency operations.
Orders for residents to leave were issued in more than a dozen areas. Evacuees were moved to hotels and at least one sports hall was turned into a temporary shelter.
Three Athens hospitals were on heightened alert, while paramedics and ambulances treated two firefighters and 13 civilians for breathing problems, a fire department spokesperson was quoted as saying.
Fire service spokesman Col Vassilios Vathrakogiannis said while there was no longer a single active fire front in the north-eastern Attica region, which includes parts of Athens, there were still “many active localised blazes”, mostly around the towns of Marathon and Penteli, according to the BBC.
One body was recovered from inside a shop in the town of Vrilissia.
European nations have announced assistance for Greece after its government activated the EU’s mutual civil protection mechanism.
Italy is providing two aircraft while France and Serbia are providing one helicopter each, Col Vathrakogiannis said.
Spain, the Czech Republic and Romania are sending further vehicles, personnel, and aid.
Neighbouring Turkey is also preparing to send two aircraft and a helicopter.