Around 125 people are reported injured, many of them seriously, after two Dutch commuter trains crashed head-on.
The collision, which happened to the west of Amsterdam, involved an inter-city train and a local stopping service.
There were no immediate reports of any deaths.
The collision caused disruption to the wider rail network, including services to Schipol international airport.
Rescuers used a helicopter and dozens of ambulances to ferry the injured to hospitals.
Nearly 60 people were said to be either seriously or badly injured.
Investigators will now be looking into how the two trains came to be on the same stretch of track.