Iryo said its train was “struck from behind” by the other train.
Spain’s transport minister Óscar Puente said on Wednesday that the decision to instruct the trains to move again, without any speed restrictions, was “inexplicable”.
The leaking of the audio recordings has been criticised by some Spanish politicians.
Posting on X, Alberto Ibáñez, a member of Congress for the left-wing Sumar platform, described the leaks as “despicable”.
Irene Montero – the prime ministerial candidate for the left-wing Podemos party – said responsibility for the crash should not be placed on one worker, adding that train drivers and experts have been warning against the liberalisation of the railway sector for years.
From the crash site, Sánchez said: “We are working day and night not only to support the victims’ families, but also to establish every last detail of this tragedy and strengthen safety measures to ensure it never happens again.”
Most Spanish politicians have cancelled all public engagements and suspended their campaigning ahead of a snap election on 29 November.
The exception is the far-right party Vox. Its leader, Santiago Abascal, said his party would not take part in what he described as attempts to “use mourning to silence criticism” of the country’s rail infrastructure.
Overnight, around 1,500 people gathered outside the Spanish Transport Ministry building in the capital, according to Spanish broadcaster TVE, which reported that demonstrators were largely calling for the resignations of Sánchez and Puente.
Police used tear gas to disperse crowds after protesters hurled bottles and flares. No injuries or arrests were reported.
Rail drivers went ahead with a planned strike on Thursday, with the Spanish Union of Railway Drivers (Semaf) saying the strike action was being held “in defence of railway safety”.
The leader of Spain’s main opposition People’s Party Alberto Núñez Feijóo said: “Spain has the right to know what is happening with its infrastructure.”
