Seven people have been killed and more than 50 injured in wildfires ravaging central and northern Portugal, authorities have said.

This comes after three firefighters died on Tuesday when their vehicle was trapped in flames.

Portugal’s civil protection services reported that 54 wildfires were burning nationwide, mainly in the north, with 5,300 firefighters mobilized.

France, Greece, Italy, and Spain sent eight water-bombing planes through the EU’s mutual assistance mechanism.

More than 1,000 firefighters battled through Monday night to control four separate blazes near the towns of Nelas and Aveiro, south of Porto.

TV footage showed residents frantically pouring buckets of water on rapidly advancing flames.

In Aveiro alone, the blazes have consumed more than 10,000 hectares (24,710 acres) of forest and scrubland in the last two days, the agency said.

This is roughly the same area that has been burnt by fires so far this year across the country.

The national civil protection commander, Andre Fernandes, said the three firefighters – two women and a man – had been killed near Nelas.

Four people, including a man retrieving tools from his shed, were reported dead on Monday.

Fernandes said late on Monday that the fires, which have forced the closure of two railway lines and several motorways, including part of the main road between Lisbon and Porto, could consume a further 20,000 hectares.

Experts said the weather conditions on Monday brought the highest risk of fire in northern Portugal since 2001.

Fernandes said the situation was “very complex” and that Tuesday would be “very difficult”.

Portugal’s prime minister, Luís Montenegro, who cancelled his Tuesday engagements in response to the fires, also said the country faced “some very difficult times over the next few days”.

An extreme fire warning has been extended until Thursday night.

After a wet start to the year, Portugal and Spain have recorded fewer wildfires than last year, but temperatures were above 30°C across Portugal over the weekend amid exceptionally low humidity and strong winds, which have fanned the flames.

The government increased fire-prevention funding by a factor of 10 and doubled its firefighting budget after the fires.

Scientists have said human-caused climate breakdown is driving more frequent and more deadly disasters across the world, from floods to heatwaves, droughts, and wildfires.

Human-caused climate breakdown is making heatwaves more likely and more intense, with some almost impossible without global heating.