One of Greece's worst-ever rail disasters, which claimed at least 43 lives, was due to "tragic human error", the country's prime minister has said.
PM Kyriakos Mitsotakis spoke after visiting the site of Tuesday night's head-on collision between a passenger service and a freight train.
The local stationmaster has been charged with manslaughter. The Greek transport minister has resigned.
Rescue teams are continuing to search for survivors.
The accident happened just before midnight on Tuesday. The passenger train carrying some 350 people collided with a freight train as it emerged from a tunnel after leaving the town of Larissa.
It is still unclear why the two services were running on the same track.
The stationmaster, who is in charge of signalling, denies wrongdoing and has blamed the accident on a possible technical failure.
After visiting the site, Mr Mitsotakis said everything pointed to "a tragic human error".
"Justice will do its job," he said in a televised address. "People will be held accountable, while the state will be on the side of the people."
Announcing his resignation, Transport Minister Kostas Karamanlis stated: "When something so tragic happens, it is impossible to continue and pretend it didn't happen."
Trade unions said collisions have multiple factors and the crash had highlighted chronic deficiencies, including lack of staff, broken signals and outdated facilities.
The first four carriages of the passenger train were derailed and the first two caught fire and were "almost completely destroyed", Thessaly regional governor Kostas Agorastos said.
The train was travelling from Athens to Thessaloniki, which has a sizeable student population, and it is believed many on board were students returning there after a holiday for Greek Orthodox lent.
Survivors have described the chaotic scenes after the crash, with one shaken passenger telling the BBC: "People were panicking and screaming."
Giannis Antonoglou, who escaped from the fifth compartment of the passenger train, said the windows suddenly smashed and "we ended up being tilted 45 degrees as if about to tip".
Stergios Minenis, a 28-year-old passenger who jumped to safety from the wreckage, told Reuters news agency: "The fire was immediate. As we were turning over we were being burned."
Some passengers said they were forced to break carriage windows with their bodies or luggage to escape the burning wreckage.
Larissa's mayor said some of those who died would only be identifiable through genetic testing.
Relatives of missing passengers have provided DNA samples to help the identify bodies, a hospital in Larissa said.
BBC
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