Irish travellers have been forced to flee holidays with nothing but the clothes on their backs as wildfires fuelled by extraordinary heat tear through southern Europe.

Wildfires in France, Spain, Portugal and Greece have burned up an area twice the size of Manhattan. More than 10,000 people have been evacuated from a mountainous area near Perpignan as a blaze threatened villages close to France’s southern border with Spain.

“As we were going to the airport, we could see the fires burning near Perpignan. We could see the smoke. We were wondering if the flight would leave, the children were worried about their safety,” said Orlaith Darcy (48), whose belongings were burned in a wildfire that destroyed the campsite where she had been staying.

Darcy, a radiographer from Mullingar, flew back to Ireland on Sunday. She fled the luxury Yelloh Village Le Brasilia campsite in beachwear with her husband and four teenagers with only their passports after smoke began billowing towards them.

A walkway at the campsite before the fire. Photograph: Orlaith DarcyA walkway at the campsite before the fire. Photograph: Orlaith Darcy The walkway after the fire. Photograph: Orlaith DarcyThe walkway after the fire. Photograph: Orlaith Darcy

A wildfire tore through the site “minutes” later, incinerating 281 bungalows on Thursday, including the one where they had been staying, in the resort near the Spanish border in the French region of Languedoc-Roussillon.

“It just happened so fast. It was pretty frightening,” said Michael Cleary (45), a schoolteacher from Mullingar who ran from the campsite with his wife and two children after seeing the smoke. He arrived back in Ireland on Friday.

The Yelloh Village La Brasilia campsite in southern France before the fire. Photograph: Sonya KellyThe Yelloh Village La Brasilia campsite in southern France before the fire. Photograph: Sonya Kelly The Yelloh Village La Brasilia campsite after the fire. Photograph: Sonya KellyThe Yelloh Village La Brasilia campsite after the fire. Photograph: Sonya Kelly

“We flew home in the clothes that we were in on the beach. I had on swimming shorts, a hat, and a T-shirt, and flip flops,” Cleary recalled. “Everything, everything went in the fire.”

Smoke rising near the Yelloh Village Le Brasilia campsite. Photograph: Michael ClearySmoke rising near the Yelloh Village Le Brasilia campsite. Photograph: Michael Cleary

Cycling’s Tour de France is taking place in the region without spectators due to the risk of fires, as a second heatwave takes hold in southern Europe not long after a “heat dome” in June caused a surge in deaths and France’s hottest ever day.

Temperatures in the nearby city of Perpignan are due to reach 39 degrees on Wednesday, while heat warnings are in place in Spain and Portugal where peaks are forecast of well over 40 degrees.

Burned houses and car in a residential area of the town of Ille sur Tet in the southern France department of Pyrenees-Orientales. Photograph: Jean-Christophe Milhet/AFP via GettyBurned houses and car in a residential area of the town of Ille sur Tet in the southern France department of Pyrenees-Orientales. Photograph: Jean-Christophe Milhet/AFP via Getty

In Greece, authorities in Thessaloniki urged residents to stay inside and shut their windows after a nearby recycling plant burned up in a wildfire, causing a toxic haze to settle over the city.

A Copernicus satellite image showed a vast plume of smoke from Portugal’s wildfires stretching for 620 kilometres over the Atlantic Ocean.

Smoke billows after a wildfire passed through the outskirts of Montalba-le-Chateau, in the Pyrenees-Orientales department. Photograph: JC Milhet/AFP via Getty ImagesSmoke billows after a wildfire passed through the outskirts of Montalba-le-Chateau, in the Pyrenees-Orientales department. Photograph: JC Milhet/AFP via Getty Images

The European Commission announced that water-bombing aircraft from Cyprus and Sweden were on their way to assist firefighters struggling to get wildfires in the French Pyrenees under control.

“As Portugal and France face an extreme wildfire threat during this severe heatwave, every minute matters,” emergency response commissioner Hadja Lahbib said in a statement.

Europe’s summer wildfire season is becoming “longer, earlier and more destructive”, according to the commission, which has said that a record 777 firefighters and 27 aircraft are being sent to help the worst affected countries this year.

Irish woman recalls moment her family knew they had to flee French wildfiresOpens in new window ]

Temperatures could reach 30 degrees in Ireland as new heat dome forms over EuropeOpens in new window ]