A high-speed train crash has killed at least 68 people and injured dozens more in central Spain.

It occurred when a train travelling from Madrid to Seville barrelled into another train - which was stationary on the tracks - on Wednesday morning. The force saw several carriages fall down an embankment.

The transport minister said a computer failure followed by human error caused the collision, which is one of the worst in Europe's modern history, and Spain's deadliest train disaster in 13 years.

Survivors described harrowing scenes of passengers being thrown into the air, trapped in the wreckage and smashing windows to get out.

The collision happened just after 09:00 (08:00 GMT) around 140km (100 miles) south of Madrid.

The stationary train, run by private rail operator Iryo, had 147 passengers on board, and had stopped on the tracks because of a computer failure, Spain's Transport Minister Óscar Puente said.

He explained that when there is a system failure, a 24-hour control centre in Madrid takes over, but it had made an "inexplicable" decision to instruct the trains to move again, without any speed restrictions.

Iryo said its train was "struck from behind" by another train, run by Spain's state-owned railway company, Renfe, which was carrying 397 passengers.

The force of the crash was "brutal", said 62-year-old passenger Salvador Arriza who was sitting in the Renfe-operated train.

Passengers started breaking the windows to get out, he told Reuters, adding that "some people couldn't move because they were trapped amongst the seats."

One of the carriages caught fire, and passengers described devastating scenes of trapped people crying and bleeding, with some buried under debris.

Pictures show that a long piece of railway track had speared through one of the carriages.