Commuters in Madrid have described the terror and chaos as a series of blasts ripped through trains in the Spanish capital.
Hospitals have been hard pressed to deal with the scale of the carnage
The morning rush hour came to a standstill as emergency services dealt with scores of people killed and more than 1,400 injured in the blasts.
"There were pieces of train in the street and dead people trapped in the twisted iron," one resident told BBC News Online.
The ambulances continued to arrive many hours later Ken Seal, who lives near Atocha station, told our website.
Atocha, one of Madrid's major stations in the centre of the city, was the scene of the main attack.
"All hell broke loose, hundreds of police cars and helicopters everywhere.. and an endless procession of ambulances that continue to arrive at the scene even now as I type nine hours later," Mr Seal said.
One man, whose house is next to the railway line, told BBC News Online what happened:
"The second blast woke me up. My bed and the whole building moved and there was a huge sound. When I opened the window there was a smell of burning plastic and clouds of smoke," he said.
"When I went down the street I saw the train - six carriages with three big holes - some people were walking down the rails and many dead and injured were lying on the ground," he added.
"I saw many things explode in the air, I don't know, it was horrible," said civil servant Juani Fernandez, 50, on the platform at Atocha station when the blasts happened.
"People started to scream and run, some bumping into each other and as we ran there was another explosion.
"I saw people with blood pouring from them, people on the ground," he told the Associated Press news agency.
Student Isabel Vega, still visibly shaken by the experience, told Spanish media: "It has been chaotic, horrific.
"You could hear people screaming, on the platform there were dead and injured, people were running covered in blood."
Francisco Torres, from Madrid, told BBC News Online he was travelling in a train about 50 metres from one of the blasts at Atocha station and could feel the carriage shake.
"People got off quickly but I still feel we all kept calm. It was only one minute later that two more bombs exploded in rapid succession.
"It was at this point that people rushed out of the station. People crying. It was shocking."
Emergency worker Oscar Romero said the devastation was the worst he had seen in his job.
"There were people destroyed, blown up, without legs," he said. "There were two cars in pieces with bodies underneath."