Emergency services, drones and dog unit continue to comb carriages as Civil Guard sets up clinics for relatives to provide DNA samples

• How did the Spain train crash happen and what will investigators be asking?

Spain began three days of mourning on Thursday for at least 69 people who died in a high-speed rail collision, as hospitals continued to treat dozens of injured passengers and train drivers went on strike to urge more investment in railway safety.

The trains – one from Spain’s state-owned Renfe and the other from the private rail company Iryo – were travelling from Madrid towards the southern region of Andalucía on Wednesday when they collided just before 9am. After the Iryo train came to a halt, the other slammed into its rear, knocking several carriages off the track near Urda in the central region of Castilla-La Mancha.

Emergency services, drones and dog unit continue to comb carriages as Civil Guard sets up clinics for relatives to provide DNA samples

• How did the Spain train crash happen and what will investigators be asking?

Spain began three days of mourning on Thursday for at least 69 people who died in a high-speed rail collision, as hospitals continued to treat dozens of injured passengers and train drivers went on strike to urge more investment in railway safety.

The trains – one from Spain’s state-owned Renfe and the other from the private rail company Iryo – were travelling from Madrid towards the southern region of Andalucía on Wednesday when they collided just before 9am. After the Iryo train came to a halt, the other slammed into its rear, knocking several carriages off the track near Urda in the central region of Castilla-La Mancha.

High-speed service travelling from Madrid to Seville ran into back of another, knocking two carriages off track

• Spain train crash – latest updates

The Spanish prime minister has declared three days of mourning after at least 68 people were killed and dozens more injured in a collision between two high-speed trains in central Spain.

The trains were travelling in the same direction on the line that stretches from the Spanish capital, Madrid, to Seville on Wednesday when one of the trains ran into the tail of the other that had stopped, knocking several carriages off the track.