At least 62 people were killed and dozens injured after a raging wildfire swept through central Portugal's Pedrógão Grande region over the weekend. Portuguese Prime Minister António Costa described the incident as "the biggest tragedy of human life that we have known in years.” The country has declared three days of national mourning for the victims of the blaze “which has caused an irreparable loss of human life,” according to a government statement, BBC reported.

The current death toll due to the deadly wildfire is reported to be highest in Portugal since the Sintra forest fire that killed 25 soldiers in 1966. 

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What caused the inferno?

The blaze is believed to have been sparked Saturday due to lightning in the Pedrógão Grande region, 150 kilometers (95 miles) northeast of Lisbon. A tree hit during a dry thunderstorm was found by the investigators, the head of the national judicial police, José Maria de Almeida Rodrigues told Portuguese media, CBS News reported. Several people were trapped in cars as raging fire swept across the road, officials said.

“Everything points very clearly toward natural causes,” said Rodrigues. “We’ve even found a tree that was struck by lightning. We’ve managed to determine that the fire was caused by thunderstorms,” he was quoted as saying by Express.

“This is a region that has had fires because of its forests, but we cannot remember a tragedy of these proportions. I am completely stunned by the number of deaths,” Valdemar Alves, Mayor of Pedrogao Grande, was quoted as saying by the Associated Press agency. 

In the recent days, several parts of Portugal and Spain have been hit by a heat wave with mercury shooing up to 40 degree Celsius (104 degrees Fahrenheit), Telegraph reported.

Portugal's National Authority for Public Safety Friday warned of wildfire due to hot and windy weather. The raging fire should serve as an urgent reminder that the government needed to improve its forestry management, the Portuguese branch of the World Wildlife Fund asserted, according to a report published by the New York Times.

Four other wildfires were reported elsewhere in Portugal on Sunday, the AP reported, but the one in Pedrógão Grande was responsible for all the deaths.

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According to AccuWeather Meteorologist Tyler Roys, heat will slowly throttle back across Portugal through the week with high temperatures falling from 99 F (37 degree Celsius) on Monday to 86 F (30 degree Celsius) by Friday.

Rescue ops continue

Schools will remain closed for now in Pedrógão Grande and several centers have been set up by the government to help people the scene, the government said in comments broadcast by state broadcaster RTP.

Around 1,600 firefighters have been deployed at the site to contain the damages, the NYT reported

European Union officials in Brussels said Sunday that the blocs' civil protection mechanism had been activated to send reinforcements to Portugal. The EU also said it would provide firefighting aircraft. While Spain sent two planes, France had also offered three aircraft.

“All our thoughts are with the families and friends of those affected by the deadly forest fires that have struck several parts of Portugal.  The European Commission's Emergency Response Coordination Centre (ERCC), which monitors natural disasters 24/7, is in constant contact with the national civil protection authorities," Christos Stylianides, the European Commission's aid chief said in an official statement. The EU's emergency center has sent a liaison officer to the country, the statement said.

French President Emmanuel Macron expressed solidarity with the victims on Twitter.

British Foreign Secretary Boris Johnson also expressed his condolences.