The government has promised a thorough investigation into the causes of one the worst train disasters in the history of Greek railways, according to the Greek national news agency AMNA
Many passengers were starting long weekend holiday; some carriages ripped apart in tunnel
Images published by Turkish media showed some wagons had derailed and debris from the train scattered on the rail track, which was covered in snow
Dramatic pictures posted by commuters showed a train carriage that appeared to have smashed right through the station concourse