PEDROGAO GRANDE, Portugal — A raging forest fire in central Portugal killed at least 62 people as they desperately tried to flee, charring cars and trucks as it swept over roads.

The disaster — the worst tragedy Portugal has experienced in decades — shook the nation, with the president declaring that the country’s pain “knows no end.”

Almost 24 hours after the deaths Saturday night, fires were still churning across the forested hillsides of central Portugal. Police, and firefighters were searching charred areas of the forest and isolated homes, looking for more bodies.

“It is a time of pain but also a time to carry on the fight” against the flames, President Marcelo Rebelo de Sousa told the nation in a televised address Sunday evening after the government declared three days of national mourning.

A huge wall of thick smoke and bright red flames towered over the tops of trees in the forested Pedrogao Grande area, 95 miles northeast of Lisbon where a lightning strike was believed to have sparked the blaze Saturday.

Investigators found a tree that was hit during a “dry thunderstorm,” the head of the national judicial police said.

Dry thunderstorms are frequent when falling water evaporates before reaching the ground because of high temperatures. Portugal is prone to forest fires in the dry summer months, and temperatures as high as 104 degrees hit the area in recent days.

At least four other significant wildfires were burning Sunday in Portugal, but the one in Pedrogao Grande was responsible for all the deaths.

“The dimensions of this fire have caused a human tragedy beyond any in our memory,” said Prime Minister Antonio Costa said Sunday. “Something extraordinary has taken place, and we have to wait for experts to properly determine its causes.”

Interior Ministry official Jorge Gomes said authorities were worried about strong winds that could help spread the blaze further.

More than 350 soldiers on Sunday joined the 700 firefighters in the fight against the blaze.

The forest fire deaths were the biggest in memory in Portugal, which saw 25 Portuguese soldiers die fighting wildfires in 1966. Last August, an outbreak of fires across Portugal killed four people, including three on the island of Madeira, and destroyed huge areas of forest.

State broadcaster RTP showed terrifying images of people on a road trying to escape the intense smoke that had reduced visibility to a few yards. A young man shared a bottle of water with a distraught woman as she stumbled down the road.

Gomes told RTP that at least 30 people died inside their cars as they tried to flee between the towns of Figueiro dos Vinhos and Castanheira de Pera.

He said 17 others died right outside their cars or by the road, 11 people died in the forest, and two people died in a car accident related to the fire. Information wasn’t available on the other deaths.

Gomes said 54 people were also injured in the fire, five of them seriously. Among them were four firefighters and a minor.

Costa tweeted his “deepest regret for the victims and a word of encouragement and strength for all who help combat this scourge.”

“We are most likely facing the biggest tragedy of human life that we have known,” he said.

The European Union responded to Portugal’s call for assistance. As a result, Spain sent four firefighting aircraft on Sunday, France was sending three and Greece’s prime minister also offered firefighting help.

Many world leaders, including French President Emmanuel Macron, Pope Francis and Indian Prime Minister Narendra Modi, expressed solidarity with Portugal.

Spanish Prime Minister Mariano Rajoy tweeted that he was “overwhelmed by the tragedy at Pedrogao Grande. The Portuguese people can count on our solidarity, support and care.”

In Kazan, Russia, Portugal’s national soccer team wore black arm bands and stood for a moment of silence with the Mexican team in solidarity with the victims. The ceremony took place before the teams’ match Sunday at the Confederations Cup tournament.

Coach Fernando Santos, superstar Cristiano Ronaldo and the rest of the players released a statement saying “in this sad hour, we send our deepest sympathies to the families, friends and loved ones of the victims of the fires.”

FIFA President Gianni Infantino, attending the match in Russia, also offered his condolences.

“We want to send a big hug to everyone in Portugal for what they are going through, which is absolutely terrible. There are no words for that,” he told reporters.