A high-speed train collision in central Spain killed at least 68 people, according to initial reports. The accident occurred on Wednesday morning in the Castilla-La Mancha region. The train operated by Spain’s state railway operator Renfe collided with a stationary train belonging to the private company Iryo.

Rescuers are still searching the wreckage for survivors. Investigators are examining the incident, which is believed to have been caused by a signal failure. The collision involved two trains traveling in the same direction. No official cause has been confirmed yet.

This is the second major train accident in Spain this year. The government has announced a three-day mourning period in response to the tragedy. Officials have not yet released details about the number of injured or the full extent of the damage. The incident has raised questions about railway safety in the country.