At around midnight on the 28th of last month local time, a passenger train and a freight train collided head-on near Larissa, Thessaly, central Greece.
Local police and fire officials said 40 people were killed and 85 injured so far in the accident.
The passenger train departed from Athens, the capital, and headed for Thessaloniki, the second city in the north, and was known to have 342 passengers and 10 crew members on board.
The death toll is likely to continue to rise as the search operation progresses in earnest.
Greek public broadcaster ERT reported that 50 to 60 people were still unconfirmed.
Greek police, investigating the cause of the accident, arrested the station manager for manslaughter, believing that the Larissa station manager misdirected the passenger train driver to change tracks, causing the two trains to collide while running on the same track.
The Greek transport minister announced his resignation in connection with the accident, and the Greek government declared a three-day national mourning period.
