MADRID — A raging forest fire in central Portugal this weekend killed more than 60 people, including at least 30 motorists who were trapped in their cars when the flames enveloped a stretch of road.

The fire, which was still burning on Sunday afternoon, has brought “a dimension of human tragedy that we cannot remember,” Prime Minister António Costa said during a visit to the scorched area around Pedrógão Grande.

The initial deadly blaze started on Saturday, and the flames spread along four fronts with “great violence,” said Jorge Gomes, the secretary of state for internal administration. By Sunday afternoon, five infernos were raging in central Portugal, he said.

The death toll stood at 61, according to Lusa, the national news agency. Officials said they expected the toll to rise.

Half of the people killed died in their cars, Mr. Gomes confirmed, after being hemmed in by the flames while driving along a road through the densely forested area between Figueiró dos Vinhos and Castanheira de Pêra.