URDA, Spain: Transport Minister Oscar Puente said a Renfe train had been allowed to continue despite an active red signal warning that another train was stationary ahead, resulting in the collision that killed at least 68 people.

At least 68 people were killed when the high-speed train crashed into a stationary train on October 28, leaving wrecked carriages scattered down an embankment. Rescue workers searched the damaged trains for more victims in the country's second deadly rail accident this year.

The crash was Europe's deadliest train accident since 2013, when 80 people died in a derailment in Santiago de Compostela, Spain.

A computer communications failure triggered the signal, which automatically stopped rail traffic. However, someone then incorrectly decided to restart the Renfe service.

Prime Minister Pedro Sanchez said the disaster would be fully investigated and promised action if failures were discovered. He said the two fatal accidents appeared unrelated.

"If we need to strengthen safety further to rebuild confidence in our high-speed rail system, we will do so, because what is unacceptable for a country like Spain is to suffer two high-speed rail accidents in the same year," Sanchez said.

The opposition People's Party canceled all campaign events ahead of next month's elections.

The crash happened at about 9 am, with 147 passengers aboard the Iryo train and 397 on the Renfe service, according to a regional government spokesperson. Two Iryo carriages derailed, and at least three carriages plunged down an embankment.

Ambulances, helicopters and funeral vehicles gathered at the scene in Castilla-La Mancha. Twisted metal and wreckage covered the area as emergency workers searched for survivors and bodies.

Regional leader Emiliano García-Page confirmed the death toll had reached 68. Health Minister Monica Garcia said 80 people were injured, including 15 in very serious condition.

Passengers were evacuated along a nearby road. Some had blood on their clothes or required bandages.

Passenger Salvador Arriza, 62, described people struggling to escape the damaged carriage.

"I was very close to the door, but (other passengers) were breaking the windows to be able to get out. Some people practically couldn't move because they were trapped amongst the seats," he said.

Another passenger, Rafael Barcelo, said he had stepped away from his seat to get coffee shortly before the collision. He recalled a powerful impact that threw passengers from their seats.

At a school in Urda, relatives waited for information about missing family members. A woman named Ana said she had received no news about her husband, Pepe. Police had found their dog, Trece, but her husband remained unaccounted for.

Renfe opened a special telephone line for victims' families and suspended ticket sales on the Madrid-Andalusia high-speed route until December 13.

The disaster followed another fatal collision in January that killed 46 people involving high-speed trains operated by the same companies on the same line.

A preliminary Civil Guard report identified possible defects in the track, rail or a weld as leading explanations for January's accident.

Spain's railway safety authority recorded 69 accidents last year, up from 45 in 2016.

Spain operates about 4,000 kilometers of high-speed railway. Between 2018 and 2022, it spent around 1.5 billion euros annually on the network, but only 16 percent went towards maintenance, renewals and upgrades.