Hundreds of firefighters are continuing to battle flames in central Portugal on Sunday from a forest fire that broke out a day earlier and has claimed the lives of at least 61 people.

"At least four other significant wildfires affected different areas of the country on Sunday," the Associated Press writes, "but the one in Pedrogao Grande," a forested area about 120 miles (200 km) northeast of Lisbon, "was responsible for all the deaths."

Scores of people were also injured.

Prime Minister Antonio Costa called it "the biggest tragedy of human life that we have known in years." He also warned Sunday that the death toll would likely rise.

Some of the victims died in their cars as they attempted to flee the flames, news agencies report.

"This is a region that has had fires because of its forests, but we cannot remember a tragedy of these proportions," said Valdemar Alves, the mayor of Pedrogao Grande. "I am completely stunned by the number of deaths," he said

Officials say lightning was the cause.

The Guardian has video of the devastation:

Portugal "and the rest of the Iberian Peninsula have been suffering a heat wave for several days, with temperatures climbing above 40 degrees Celsius, or 104 Fahrenheit, in several regions," the New York Times writes.

"I knew several of the victims," said local resident Isabel Ferreira. "One of my colleagues lost her mother and her four-year-old girl as she could not get them out of the back of the car," the 62-year-old said. 

Another survivor, 36-year-old Gareth Roberts, a Brit who's lived in central Portugal for four years, relayed his experience to the BBC.

He was driving back to his home when, about 50 minutes from his destination, an officer ordered the car off the road in the village of Mó Grande as a result of the fire. There, a family offered Roberts refuge. "Eventually the fire passed and we emerged to see the smouldering remains of the village," he told BBC. "The devastation was indescribable. People, bewildered, remains of homes burning uncontrollably, concrete posts exploding over roads," he said.

The country has declared three days of mourning for the victims.