Updated at 11 a.m. ET
A wildfire swept through central Portugal on Saturday, killing more than 60 people and injuring dozens more in what the country's prime minister called "the biggest tragedy of human life that we have known in years."
The deadly blaze, which was just one of dozens that broke out Saturday, ravaged the heavily wooded municipality of Pedrogão Grande, roughly 100 miles from Lisbon. According to officials, most of the victims died in their cars along a single road as they attempted to escape.
"Many cars could not get out, and people burned to death inside their cars," Jorge Gomes, Portuguese secretary of state of internal administration, told CNN affiliate TVI.
Officials say they expect the death toll to rise as hundreds of firefighters continue to battle the inferno in Pedrogão Grande, using aircraft and some 300 vehicles in the area. In total, The New York Times reports about 1,600 firefighters are at work attempting to quell wildfires across the country.
Eight firefighters are among the dozens of injured, CNN reports, four of whom remain in critical condition.
As Alison Roberts reports from Lisbon for our Newscast unit, officials believe a lightning strike is likely to blame for the Pedrogão Grande fire, and they have ruled out a criminal cause.
The Associated Press, citing Portuguese media, reports that investigators trace the cause to a "dry thunderstorm."
"Dry thunderstorms are frequent when falling water evaporates before reaching the ground because of high temperatures," the wire service notes. "Portugal, like most southern European countries, is prone to forest fires in the dry summer months."
"This is a region that has had fires because of its forests, but we cannot remember a tragedy of these proportions," said the municipality's mayor, Valdemar Alves, according to The AP. "I am completely stunned by the number of deaths."
The Portuguese government has declared three days of mourning to commemorate the victims, and tributes have poured in for those killed and those firefighters still battling to save other people.
"We express our condolences to those that have lost loved ones," the European Commission, executive arm of the European Union, said in a statement Sunday. "The EU is fully ready to help. All will be done to assist the authorities and people of Portugal at this time of need."
The commission said France had offered the use of three planes, which "will be quickly sent to assist the local emergency efforts. In addition, Spain has also sent aircraft on a bilateral basis."