At least 30 people were killed in the Wednesday crash, according to a spokesperson for Castilla-La Mancha, the region where it took place. The person spoke on the condition of anonymity because they were not authorized to speak publicly about the death toll.

In Spanish news reports, passengers who were in the crash described an awful impact that tossed people from a dining car, broke limbs and piled passengers atop one another. People crawled out of windows and lay in a nearby field, where local workers, who had heard the crash, rushed to help them with first aid kits and saw the first bodies.

The Adif, Spain’s rail authority, said the trains involved were a “Renfe train and another from the Iryo company, both covering the Madrid-Sevilla route.” Renfe, the national rail provider, reported that high-speed service from Madrid, the nation’s capital, to the southern region of Andalusia was suspended.

Initial reports suggested that the Iryo train was stopped on the tracks, and that the Renfe train barreled into it. Local news outlets reported that there were 397 passengers aboard the Renfe train and about 150 aboard the Iryo train.

Isaac Barrientos, a spokesman for the government’s transportation ministry, said initial reports indicated that two carriages of the Iryo train had derailed.

With early national elections set for the end of November, the crash had the potential to become an issue in an already bitter campaign about the competence of the left-wing government of Prime Minister Pedro Sánchez.

“Shocked by the serious train accident in Toledo,” Mr. Sánchez, whose office canceled all scheduled meetings, wrote on social media. “Emergency services are working on the ground to assist those affected and ensure their safety, in coordination with all the involved administrations. My affection, solidarity and support to all the victims and their families.”

The conservative opposition leader, Alberto Núñez Feijóo, quickly voiced his own concern as well.

“I am very concerned about the information we are receiving regarding another train accident,” he wrote on social media. “The priority now is to assist the victims and support their families. My full support goes to the emergency teams working on the ground.”

His Popular Party canceled all its campaign events around the country.

José Bautista contributed reporting from Madrid.