An investigation is under way in the Netherlands to establish what caused two commuter trains to collide head-on in Amsterdam yesterday evening.
About 60 people are reported to have been injured, up to 20 seriously, in the incident which occurred between Amsterdam's Central Station and Schiphol Airport.
Many of those taken to hospital are said to have sustained broken bones and neck injuries.
A spokeswoman for the Dutch capital's fire service put the number of seriously injured at 56, adding "tens of others were slightly wounded."
The accident happened at around 6.30pm (1630 GMT) when a local train leaving Amsterdam hit a high-speed train, Dutch rail network Prorail spokeswoman Babet Verstappen told AFP.
But both trains were travelling relatively slowly at the time, Dutch NOS television reported: each moving at around 50km/h.
One had just left Amsterdam central station; the other Amsterdam Sloterdijk.
Witnesses quoted by the Dutch media television said the impact had not been violent.
Emergency personnel treated some of the wounded at the scene, on a bridge between Sloterdijk and Amsterdam Central Station, Ms Verstappen added.
The worst injured were taken to hospitals, while less seriously hurt passengers were booked into hotels in the city, she added.
Many of the injured suffered from broken bones and bruising, Dutch news agency ANP reported.
It cited witnesses who described how travellers had been thrown about inside the carriages or up against their windows, some of which had shattered.
Witnesses said they heard a long hoot from one of the trains before the crash.
Passengers on Twitter said they were "smashed against the trains' frames" or "thrown from their seats", ANP added.
"Some of the injured had to be rescued from inside the train," added Amsterdam fire service spokeswoman Elke van den Hout.
By late last night, all the injured had been rescued from the trains, which remained on the tracks, railway police spokesman Kraszewski said.
The cause of the accident remained unknown, but police have launched an investigation.
The crash has shut down rail traffic in the west of the city, including Amsterdam Central station and the service to Schiphol airport, Prorail's Verstappen said.
Bus services were being laid on to try to get passengers to their destinations.
