VIDEO GUIDANCE: Contains graphic footage.
Viewers are advised that they may find the footage of the moment the passenger train left the tracks on the outskirts of the city of Santiago de Compostela disturbing.
The train had been travelling between Madrid and Ferrol when the horrific crash happened in the Galicia region on Wednesday night.
Government leaders in the UK and Ireland have extended their sympathies to their Spanish counterparts and all those caught up in the country's worst train disaster in nearly 70 years.
It is feared that the death toll could rise further as many of those injured are in serious or critical conditions in hospital.
One British person is known to have been injured.
We know that one British citizen was injured in this accident and the embassy has been providing consular support.
UK Foreign Secretary William Hague
Prime Minister David Cameron has written to Spanish Prime Minister Mariano Rajoy to express his sadness, saying: "Please pass my deep condolences to those who have lost loved ones and my thoughts and prayers to all those who have been injured."
Irish Tánaiste Eamon Gilmore also added his condolences.
"My thoughts are with those who have lost family and loved ones in this tragic accident," he said.
The Galician region and the city of Santiago is a popular destination for Irish travellers and the Irish Embassy in Madrid has been in contact with the regional authorities since the accident occurred.
"While at this stage, there is no indication of any Irish involvement, the situation is still developing and it will be some time before all of those involved have been identified."
Investigations into the cause of the train crash are likely to look at the possibility that the train was travelling too fast as it rounded a bend in the track.
It's a disaster. I've been very lucky because I'm one of the few to be able to walk out.
Sergio Prego, passenger
The historic town of Santiago de Compostela attracts tens of thousands of pilgrims every year to visit a holy shrine where the remains of St James, one of Jesus' apostles, are believed to be buried.
The date 25 July is particularly significant because it is the feast day of the saint.
People have been making the pilgrimage to the site, which is just 2.5 miles from where the train crashed, for more than 1,000 years.
The president of the Galicia region, Alberto Núñez Feijóo, has described the scene of the derailment as "Dante-esque".