A Greek air force water-dropping plane crashed while diving into a wildfire in southern Greece on Tuesday, killing both pilots, as authorities battled blazes that have been raging for days across the country amid a return of heat wave temperatures.

Summer wildfires blamed on climate change have also struck other Mediterranean countries, leaving at least 34 people dead in Algeria in recent days and two people dead in southern Italy on Tuesday.

A state ERT TV video showed the bright yellow CL-215 aircraft releasing its load of water on the island of Evia before its wingtip apparently snagged in a tree branch. Moments later it disappeared into a deep fold in the ground from which a fireball erupted.

The air force said the pilots, aged 34 and 27, both died in the crash.

Prime Minister Kyriakos Mitsotakis cancelled a planned visit to Cyprus for Wednesday, and Greece's armed forces declared three days of mourning.

“They offered their lives to save lives,” Mitsotakis said of the pilots. “They proved how hazardous their daily missions in extinguishing fires are ... In their memory, we continue the war against the destructive forces of nature.”

A third successive heat wave in Greece pushed temperatures back above 40 degrees Celsius (104 degrees Fahrenheit) Tuesday amid a string of evacuations from fires that have raged for days, whipped on by strong winds.

It's still unclear how they started, although tinder-dry conditions and the summer heat mean the slightest spark can ignite a blaze that will spread fast if not quickly quenched. Several people have been arrested or fined across Greece in recent days for accidentally starting fires.

EU officials have blamed climate change for the increasing frequency and intensity of wildfires across the European continent, noting that 2022 was the second-worst year for wildfire damage on record after 2017.

Greek police said a burned body believed to belong to a sheep farmer who had been missing since Sunday in southern Evia — a day before the fire broke out there — was found on Tuesday. It was unclear whether he had been killed by the fire or had died of other causes beforehand.

A fire service spokesman said the worst blazes on Tuesday were on the southeastern island of Rhodes and the northwestern island of Corfu — both popular tourist destinations. “On the other fronts, we have to deal with many cases of the fire flaring up again,” Ioannis Artopios said.

Four villages on Rhodes were ordered evacuated on Tuesday as a fire burning for eight days continued to move inland, torching mountainous forest areas, including a part of a nature reserve.

Another five evacuations were ordered on Corfu, and one overnight on Evia.

On Rhodes, desperate residents, many with wet towels around their necks to stave off the scorching heat, used shovels to beat back flames approaching their homes, while firefighting planes and helicopters resumed water drops at first light.

“For the twelfth day, under extreme conditions of heat and strong winds, we are fighting nonstop on dozens of forest fire fronts. ... The Greek Fire Service has battled more than 500 fires — more than 50 a day,” said Vassilis Kikilias, the minister for climate crisis and civil protection.

Authorities said more than 20,000 people have been involved in successive evacuations on the island, mostly tourists over the weekend when fires swept through two coastal areas in the southeast of Rhodes.

Among them was Serbian basketball star Philip Petrusev, a player for the Philadelphia 76ers who was vacationing on Rhodes with his partner Tiana Sumakovic.

In a series of online posts, Sumakovic described frantic scenes as she and Petrusev escaped the fire.

“The fire got got very close and we had to run,” Sumakovic wrote, captioning videos of the fire. “We were choking on the smoke and ran as far as we could ... we eventually made it to safety.”

Rhodes is highly popular with Nordic tourists, who are expected to continue heading for the island this week.

Two full charter flights were scheduled to depart from Sweden on Wednesday, Swedish newspaper Aftonbladet said. Tour operators said holidaymakers would be heading to resorts in the so-far unaffected northern part of Rhodes.

In Athens, authorities resumed afternoon closing hours at the ancient Acropolis, as part of broader measures to cope with the high heat.

The European Union has sent 500 firefighters, 100 vehicles and seven planes from 10 member states, while Turkey, Israel, Egypt and other countries have also sent help.

Contributing nations included Italy, which has its own fires and extreme weather too.

On the island of Sicily, two people were found dead Tuesday in a home burned by a wildfire that temporarily shut down Palermo's international airport, according to Italian news reports. Regional officials said 55 fires were active on Sicily, amid temperatures in the 40s Celsius. In Puglia, further north, some 2,000 tourists were evacuated from three hotels in Vieste as flames got perilously close.

But in Italy's northern Lombardy region, a powerful storm accompanied by heavy hail caused flooding and power outages and was blamed for the death of a 16-year-old girl at a scouts' camp.

In southeastern France, fire crews fought scattered wildfires, including one near Arles in Provence involving 300 firefighters and a water-dropping helicopter. Authorities banned access to several forested areas along the French Riviera and in Corsica.

In Turkey, authorities evacuated a dozen homes and a hospital as a precaution on Tuesday after a wildfire raged through a rugged forest area near the Mediterranean resort of Kemer, in Antalya province.

Another wildfire in the western province of Manisa, was brought under control a day after it burnt at least 14 homes.