Police confirmed on Sunday a wildfire raging on the Spanish tourist island of Tenerife was started deliberately, Canary Islands regional president Fernando Clavijo said.
Police have opened three lines of investigation, Mr Clavijo added, but did not say if there had been any arrests.
Improved weather allowed firefighters to make advances overnight in their battle to tame the blaze that has raged out of control for the past five days, authorities said on Sunday.
“The night was very difficult but thanks to the work of the firefighters, the results have been very positive,” Tenerife governor Rosa Davila said.
The Canary Islands have been in drought for most of the past few years, as has much of mainland Spain.
The islands have recorded below-average rainfall in recent years because of changing weather patterns caused by climate change.
Although the blaze in the north-east of the island is not near the main tourist areas of the south-west, the regional government ordered the evacuation of a state-run hotel in the Teide volcano national park, in central Tenerife, about 50km south-west of the fire zone.
It was not immediately clear how many people were staying at the hotel.
Ms Davila said more than 12,000 people have been evacuated from their homes since the fire started on Tuesday.
The islands' emergency services on Sunday said 11,600 hectares of pine forest and scrubland had been burnt.
Wildfires in Tenerife - in pictures
No injuries have yet been reported and Ms Davila said thanks to the firefighters, no houses had been burnt so far.
The fire, described as the worst in Tenerife in decades, is threatening 11 town areas flanking a steep and craggy mountain area. Access for firefighters is extremely difficult.
The emergency services said air quality in 19 town areas was not good and urged people to stay indoors when possible and wear masks outside.
More than 400 firefighters and soldiers have been posted, as well as 23 water-carrying helicopters and planes.
Spain’s mainland is bracing for another heatwave starting on Sunday, which will last until Thursday.
Spain’s state weather service said temperatures would gradually rise to hit 40ºC in parts of the mainland on Wednesday and Thursday.
On Tenerife, the agency predicted maximum temperatures averaging 30ºC for the coming week.
More than 2,000 people were evacuated in a wildfire on the nearby La Palma island last month that affected about 4,500 hectares.
Spain accounted for almost 40 per cent of the nearly 800,00 hectares burnt in the EU in 2022, the agency said.
More villages evacuated as a large wildfire in northern Greece rages for the second day
Greek authorities evacuated another five villages near the north-eastern border with Turkey on Sunday, where a large summer wildfire that has already destroyed several homes at the weekend drew dangerously close.
There were no reports of serious injuries to firefighters or residents from the forest blaze near the town of Alexandroupolis, which forced the evacuation of another eight villages on Saturday.
Strong winds whipped on the flames, and civil protection authorities warned of an “extreme” fire risk on Monday in the region around the capital, Athens, and other parts of southern Greece.
About 200 firefighters, assisted by volunteers, police and 16 water-dropping aircraft, were battling the blaze near Alexandroupolis.
Local authorities said about half a dozen outlying houses and outbuildings were badly damaged in two of the evacuated villages, as well as a church.
Sections of a motorway were closed for a second day as smoke reduced visibility, while Alexandroupolis residents were advised to keep their windows shut.
Wild fire on Rhodes and Corfu in Greece - in pictures
Greece's Minister for Civil Protection, Vassilis Kikilias, on Sunday said firefighters, police, army personnel and volunteers were “waging an intense battle” in the Alexandroupolis area and called for extreme public vigilance throughout the country on Monday.
“No outdoors work that could trigger a fire will be permitted,” Mr Kikilias said. “We must all protect our country.”
Across the border in Turkey, the governor of Erdine province said the border crossing at Ipsala had been closed until further notice because of the fires.
Greece suffers destructive wildfires every summer. Officials say they have been exacerbated by climate change.
EU officials have also blamed climate change for the increasing frequency and intensity of wildfires in Europe, saying 2022 was the second-worst year for wildfire damage on record after 2017.
The deadliest Greek wildfire on record killed 104 people in 2018, in a seaside resort near Athens that residents had not been warned to evacuate.
Since then, authorities have been erring on the side of caution, issuing swift mass evacuation orders whenever inhabited areas are under threat.
Last month a large wildfire on the resort island of Rhodes forced the evacuation of about 20,000 tourists.
Days later, two air force pilots were killed when their water-dropping plane crashed while diving low to tackle a blaze on the island of Evia.
Another three wildfire-related deaths have been recorded this summer.