The EU will send eight firefighting planes to Portugal to help the country tackle blazes in its north that have injured 12 firefighters, two seriously.
Several fires broke out in the Aveiro region over the weekend, which have forced about 70 residents to flee, the civil protection authority has said.
Police have shut motorways, including the main road between the capital, Lisbon, and Porto.
EU Commission President Ursula von der Leyen said the bloc was “urgently mobilizing” the planes and thanked four states – France, Greece, Italy and Spain – for sending the aid. She urged other member states to send further assistance in a post to X.
Around 1,500 firefighters were battling blazes across the country on Monday, Portuguese officials said. The country already owns 30 water bombers, but authorities said the complex situation required additional support.
France has agreed to deploy two water bombers, the French Interior Minister Gerald Darmanin has said. Officials in Lisbon expect two more to arrive on Monday from Spain.
“This is EU solidarity at its best,” Ms von der Leyen said, hailing the four states for showing such rapid support.
So far 18 people have been injured by the blazes, including several who have received treatment. One firefighter has died due to “sudden illness”, according to the Portuguese newspaper Diario de Noticias.
Temperatures in Portugal exceeded 30C (86F) over the weekend and are expected to remain high for days.
“The situation is not out of control, but it is very complex. Today will be a difficult day, and so will tomorrow,” national civil protection commander Andre Fernandes said.
He plans to keep for now the red alert for hot weather currently in place across mainland Portugal.
The Mayor of Albergaria-a-Velha, António Loureiro, said four houses have been burnt down and 20 more are threatened around the town as the fires rage.
Two other homes have been destroyed at Cabeceiras de Basto, in the area of ​​Braga, AFP has reported local authorities as saying.
The police say traffic has been stopped on three highways in the region.
Portugal and neighboring Spain have recorded fewer wildfires this year, largely due to a wet and rainy start to the year. But they remain vulnerable to blazes due to hot and dry conditions.
Climate change increases the risk of hot, dry weather that is likely to fuel wildfires.
The world has already warmed by about 1.1C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to emissions.