Unrestrained wildfires in Spain and France have forced more than 250,000 people to flee, authorities from both countries have said, as they struggle to contain the blazes.

About 70,000 people were evacuated from central Spain, while 197,000 people fled in France, including tens of thousands from the wine region city of Bordeaux.

Spain declared a national emergency, the first time the country has ever done so over a wildfire. France’s evacuations constituted “probably” the biggest peacetime evacuation the country has ever seen, its interior minister said.

Hundreds of firefighters have worked to contain the blazes, which have been fuelled by persistent heatwaves and the climate crisis, but were still unable to stop their advance. In Spain, high winds were exacerbating the fires, and two of the three blazes merged on Friday.

France’s interior minister, Laurent Nuñez, said a huge military cargo plane, the Airbus A400M Atlas, was being deployed to join 18 other aircraft in the “long and very difficult” battle against wildfires in the Gironde region of south-western France.

The French government has called in the military to help, deploying 1,500 soldiers, and has rushed 1.5m face masks to help protect people from smoke inhalation. Fire crews have also been digging trenches, as well as using retardants, as winds were forecast to push the fires closer to Bordeaux. Wildfires were reported to be about 20 miles west of the city.

The French government ordered people in the path of the fire to evacuate, including those in Bordeaux’s western suburbs. Police went door to door to tell people to leave, with scenes of panic unfolding as residents fled their homes under a smoke-darkened sky.

The Gironde regional prefect, Sophie Brocas, said on Friday that strong winds were driving the fire towards the Bordeaux metro area and that it had grown to “an unprecedented magnitude”.

People who have been evacuated from their homes in the Bordeaux-Lac exhibition centre, which has been turned into a shelter for displaced people. Photograph: Manon Cruz/Reuters

Officials said the sudden blazes caught residents and authorities off guard. Some people in France had to flee by boat when the flames headed towards coastal towns.

The French prime minister, Sébastien Lecornu, said the fire in Gironde was so strong that it had begun generating its own winds.

“The fires that are hitting our country have reached a level that has never been seen before,” he wrote on X. “Our priority is clear: protecting human lives.” He urged people to obey evacuation orders “without delay”.

The Spanish health minister instructed people in Madrid not to go outside over concern of the poor air quality.

“Avoid physical activity and staying outdoors. If you go outdoors and there is smoke or ash, use a mask,” Monica Garcia said on X.

On Saturday evening, Spain’s interior ministry said a man had died in a fire in Manises, in Valencia. He had been found in a car in a ravine, officials said.

Firefighters on a support line between the villages of Lacanau and Saint-Hélène in the Bordeaux region. Photograph: Astrid Lagougne/EPA

The fire was a separate incident from the major blazes raging west of Madrid, which have so far not caused any reported deaths.

The long, back-to-back heatwaves in Europe have dried forests out, turning them into tinder for wildfires. Fires had already consumed 130,000 hectares (320,000 acres) of forest this year in Spain, about a third higher than the country’s annual average, Spain’s prime minister, Pedro Sánchez, said on Saturday.

In France, fires burned down more than 98,000 hectares, which France’s interior minister said was a “historic record”.

Scientists say climate breakdown is triggering more frequent and more extreme weather events, evaporating soils and waterways, fuelling wildfires and leading to thousands of excess deaths. Europe is heating at about twice the global average rate.

Sánchez said that cooler weather on Saturday gave a “window of opportunity” for firefighters to help contain the blazes. “We are going to have some complex hours ahead because, although the temperatures have gone down, we do not know exactly how the wind will develop, how strong it will be,” he added.

Other European countries were helping both countries fight the blazes, with Croatia, the Czech Republic, Greece, Italy, the Netherlands, Portugal and Slovakia sending aid and water-dumping aircraft to France and Spain.

The European Commission president, Ursula von der Leyen, promised more help was on the way.

“Europe stands alongside France and Spain in the face of the devastating wildfires ravaging them. Five planes and two helicopters from the rescue fleet are now deployed in France and four planes are arriving in Spain today,” she said on X.