Several Americans were hurt, according to the State Department, which did not provide further details.

Jacksonville firefighter Josue Garcia-Otero was on board with seven of his family members.

“We got to safety first, then began treating other patients that were critically injured,” Garcia-Otero said in a news release issued by the Jacksonville Fire and Rescue Department. “My wife is a nurse, and she was helping too.”

Pledging an investigation and improvements to prevent a similar tragedy in future, Sánchez said it was clear that we need to reinforce the safety of our train service to rebuild the trust in our high-speed rail.”

It was “not acceptable for a country like Spain to endure two high-speed train accidents in the same year,” he said, referring to an incident in January when 46 people died after one train jumped the track and slammed into the side of another going the opposite way in the south of the country.

Both crashes involved trains operated by the state-owned RENFE company and the privately owned IRYO.

Oscar Puente, Spain's transport minister, addresses the media after the crashAngel Martinez / Getty

His transport minister, Óscar Puente, said that the crash was caused by what he called the “inexplicable” order from a central command center for Spain’s trains after a security system had failed.

Puente, who is facing calls to resign, said the train engineers were not to blame, but instead a security system had stopped working because of a computer malfunction, causing all trains on the line to stop at about 8:30 a.m. local time (5:30 a.m. ET).

Shortly afterwards he said central command had told the RENFE train to start running again without any speed restrictions, adding that never should have happened and it ended up colliding with the stationary IRYO train at 8:53 a.m.

A protest outside Spain's transport ministry on Wednesday night.Ananda Manjon / Europa Press via Getty

Riot police used tear gas outside his transport ministry in Madrid late Wednesday after far-right protesters gathered outside and pushed against a cordon set up by officers. Some threw flares and other objects as some chanted slogans against Puente and Sánchez.

Quite what effect the accident will have on Sánchez’s political ambitions remains unclear. The prime minister called a snap election next month after his Socialist party suffered several defeats on legislation aimed at addressing the country’s housing crisis.

Signs reading "Corruption kills" during a protest in Plaza de Cibeles in Madrid.Fernando Sanche / Europa Press via Getty

His minority government had put forward two decree laws aimed at protecting tenants in the rental market after nationwide protests following the eviction of an 87-year-old woman from her Madrid apartment. Maricarmen Abascal, who was a wheelchair user, was eventually allowed to return but died in hospital before she could do so.

Sánchez who took power in 2018 has weathered several crises during his premiership including the Covid-19 pandemic and the global inflation rise.

But he has faced attacks from right-wing parties over his liberal migration policies and accusations of corruption against his party and his wife, which both deny, and polls show he is facing and uphill battle to win votes ahead of the election next month.