Leaked audio recordings reveal that Spanish train controllers cleared a high-speed Renfe train to proceed moments before it struck a stationary Iryo train near Urda on Wednesday, killing 69 people in one of Europe's worst modern rail disasters.

The three audio recordings, published by Spanish media outlets including El País and RTVE, show a control centre operator telling the Renfe driver to "continue your journey and then proceed under Lateral Signalling Block, at normal speed with normal operation." The Lateral Signalling Block is a backup system used when automatic signalling fails.

In separate recordings, the Iryo train's driver reported that the train could not move and remained stationary at Urda's entry signal. A later recording suggests the controller was notified the Iryo train was still stopped as the Renfe train approached.

Spain's transport minister Óscar Puente called the decision to instruct trains to move again without speed restrictions "inexplicable." He said the order came in "error." A reported computer failure in the automatic signalling system had forced all trains to halt on the affected stretch.

The Renfe train, run by state-owned operator Renfe, carried 397 passengers. The Iryo train carried 147 passengers. Dozens were injured. Survivors described people crying, bleeding and trapped in seats, with one carriage catching fire.

Spain began three days of national mourning on Thursday. King Felipe VI and Queen Letizia visited injured passengers in a hospital in Toledo. Prime Minister Pedro Sánchez pledged that investigators would determine why the crash occurred and what measures would prevent future incidents.

The leak of the audio recordings drew criticism from some Spanish politicians. About 1,500 people gathered outside the transport ministry building in Madrid on Wednesday night calling for resignations. Police used tear gas to disperse crowds after protesters hurled bottles and flares, with no injuries or arrests reported.

Rail drivers held a planned strike on Thursday "in defence of railway safety," according to the Spanish Union of Railway Drivers.