The accident happened just before midnight on Tuesday evening. The locomotives and the first cars of both trains were almost completely destroyed by the collision, both drivers are among the dead. Several wagons fell off the tracks and some caught fire.
As of Wednesday afternoon, 36 dead had been recovered and 66 injured had been taken to hospital. According to the fire brigade, the number of victims could increase because people were still believed to be in the pile of rubble. "The effort to free trapped people continues," said fire department spokesman Vassilis Vathrakogiannis.
The rescue work is "very difficult," said Konstantinos Giannakopoulos from the doctors' union in Larisa on the ERT television channel. Some of the 500 rescue workers tried to get into the crushed wagons with metal scissors. The wrecks lying next to the railway line were lifted with two large cranes. Regional governor Kostas Agorastos said on Skai that the death toll will probably be "very high" in the end.
Greek government spokesman Giannis Oikonomou said the trains had been traveling "several kilometers" on the same track before the accident. According to the police, the Larisa station master was arrested.
OSE train drivers' union leader Kostas Genidounias said the line between Athens and Thessaloniki was in a very bad condition. All signals are controlled manually, he said on television station ERT. "The systems haven't worked since 2000." The Italian state railway Ferrovie di Stato, which took over the Greek railway company Hellenic Train in 2017, initially did not comment on request.
"I've never seen anything like it in my life," said a rescue worker who came out of a wrecked wagon, completely exhausted. "It's so tragic."
"It was a nightmare, I'm still shaking," Angelos, 22, told the AFP news agency at the scene of the accident. "Fortunately we were in the penultimate carriage and got out alive." The collision felt like a "huge earthquake". "There was a fire in the first wagons and total panic," he reported.
"At the moment of the accident, the windows suddenly exploded," another passenger reported on television. "Fortunately we were able to open the door and escape quickly. People couldn't do it in other cars."
Health Minister Thanos Plevris said many young people were sitting on the passenger train with a total of 342 passengers. According to him, many students had taken the train to go back to Thessaloniki after a long weekend.
Prime Minister Kyriakos Mitsotakis visited the scene of the accident on Wednesday and declared three days of national mourning. He promised to fully clarify the circumstances of the accident. The accident also caused great dismay abroad. "My thoughts are with the people of Greece this morning," wrote EU Council President Charles Michel on Twitter.