At least 68 people were killed and dozens injured when a high-speed train crashed into another train that had stopped on the tracks in Spain on Wednesday, marking the country's second deadly rail collision this year.

The regional government of Castilla-La Mancha confirmed the death toll, saying another 58 people were receiving treatment at hospitals. Rescue teams continued searching the wreckage throughout the day for survivors and bodies.

The collision occurred just nine months after another deadly crash involving high-speed trains operated by the same two companies in southern Spain in January.

"Today all of Spain is grieving," Spanish Prime Minister Pedro Sánchez said during a visit to the crash site, announcing that his government would declare three days of national mourning.

Sánchez called for stronger safety measures to restore public confidence in the country's high-speed rail system, which was once a source of national pride.

"It is unacceptable for a country like Spain to suffer two high-speed rail accidents in the same year," Sánchez said. He faces an election on November 29.

Spain's railway infrastructure operator ADIF said the accident occurred on Wednesday morning in the central province of Toledo, involving two high-speed trains carrying hundreds of passengers and travelling south from Madrid towards Seville.

A train operated by state-owned RENFE struck the rear of a stationary train operated by private company IRYO. The collision derailed two rear carriages of the IRYO train and the front of the RENFE train.

Samy Paul, a British tourist who was rescued from the RENFE train, described the impact to The Associated Press.

"Suddenly, everything started falling apart. Bang! We fell down," he said. "We realized carriage two, carriage one, all gone, all smashed. There was blood all over."

David Gómez, a construction worker who was working nearby, told Spanish newspaper El País that he rushed to help after hearing the crash.

"People were trying to get out through the windows ... We cut through some fences to access the area and treated people with the first-aid kits we had brought until emergency services arrived," he said.

He added that while trying to pull a young woman from the wreckage, he found a severed leg.

Rail services between Madrid, Ciudad Real and Andalusia were suspended following the collision.

Transport minister points to 'inexplicable' decision

Spanish Transport Minister Óscar Puente blamed what he described as an "inexplicable" decision by the central command centre responsible for the country's rail network after a safety system failed. He said the train drivers were not responsible for the crash.

Puente said the safety system on a 63-kilometre (39-mile) stretch of track stopped functioning at 8:30am because of a computer malfunction, forcing all trains in the affected section to stop.

However, the central command centre subsequently instructed the RENFE train to resume running without any speed restrictions. It collided with the stationary IRYO train at 8:53am, he said.

According to the minister, the RENFE train should not have been allowed to move while a stop signal remained active on the line. Even if it had been permitted to proceed, it should have been instructed to travel at a reduced speed.

Authorities were still examining data to determine the train's speed at the time of the collision, but it might have been travelling at up to 200 kilometres per hour (124 miles per hour), Puente said.

"I am not attributing responsibility to anyone, I am just stating the facts," he said.

Passengers describe terrifying impact

The collision occurred on a flat stretch of railway surrounded by olive groves between the towns of Urda and Los Yébenes. It left carriages torn into pieces of metal and other debris scattered down a gravel slope.

Ignacio Relaño, a passenger on the RENFE train, told state broadcaster TVE that the train had briefly stopped before moving again and crashing into the IRYO train.

"We all felt the train abruptly slowing down and then the impact," he said.

"The car leaned to one side like it was about to tip over. I hit my nose, everything went flying, luggage, cell phones. Everything shook," he added.

Authorities said the RENFE train was carrying 397 passengers, while 147 people were aboard the IRYO train.

Ambulances and medical helicopters transported the injured from the scene, while uninjured survivors were evacuated by bus. A military emergency brigade was also deployed to assist rescue operations.

Spain's King Felipe VI visited the crash site.

"We share in the grief of the families and loved ones of those who lost their lives, and we send our heartfelt support to the injured and all those affected," the Spanish royal family said in a statement.

European Commission President Ursula von der Leyen also expressed condolences, saying, "My heart goes out to the victims' families and loved ones. Today, Europe mourns with you."

Spain's football federation postponed all 24 Copa del Rey matches scheduled for Wednesday.

Second deadly rail collision this year

The wreckage of Wednesday's accident recalled the January collision in southern Spain that killed 46 people when an IRYO train derailed and struck an oncoming RENFE train. The impact sent the first two carriages of the struck train down a four-metre (13-foot) slope.

That accident was Spain's deadliest rail disaster since a 2013 crash that killed 80 people.

Before this year, Spain had not experienced a fatal accident on its dedicated high-speed railway lines since the network opened in 1992.

Spain among global leaders in high-speed rail

Spain has invested heavily in high-speed rail over recent decades, becoming one of the world's leading countries in the sector.

The country's railway union defines high-speed rail as lines designed for trains travelling at 250 kilometres per hour (155 miles per hour) or faster.

Spain has built around 3,900 kilometres (2,400 miles) of such railway lines over more than three decades for its population of 49 million. Only China, with 45,000 kilometres (28,000 miles) of high-speed tracks serving a population of 1.4 billion, has a larger network, according to the International Union of Railways.

Spain only recently opened its rail network to private operators to compete with state-owned RENFE. Italian-owned IRYO began operating in the country in 2022.

Joan Rodríguez, a spokesperson for Spain's train workers' union, said the increase in rail traffic following the sector's liberalisation had placed additional pressure on the infrastructure.

"We are not convinced that the liberalization of the high-speed passenger rail service was matched by the necessary upkeep of the lines," Rodríguez told TVE on Wednesday.

"I am not saying it was a determining factor (in the crashes), but yes, the increase in use of the network is a factor to keep in mind," he added.