Comment: What is UP with all these train crashes of late??
© Vaggelis Kousioras / APRescue workers search for trapped passengers at the crash site.
Eleni Zaggelidou, one of ten coroners working on the investigation, said DNA had been taken from 57 intact bodies.
Meanwhile, a government minister said austerity during Greece's economic crisis in the 2000s contributed to a lack of investment in the railways.
Rail workers held a one-day strike on Thursday following the disaster, blaming government neglect.
The walkout follows protests in Athens, Thessaloniki and the city of Larissa, near the site of the disaster.
Rescue workers are still going through burned and buckled carriages there, searching for victims.
This was the "most difficult moment", rescuer Konstantinos Imanimidis told Reuters news agency, because "instead of saving lives, we have to recover bodies".
The incident happened just before midnight on Tuesday. A passenger train carrying 350 people collided with a freight train after both ended up on the same track - causing the front carriages to burst into flames.
The railway workers' strike began at 0600 local time (0400 GMT), affecting national rail services and the subway in Athens.
Many in Greece see the crash as an accident waiting to happen, and the union blamed successive governments' "disrespect" towards Greek railways for leading to this "tragic result".
During a visit to a hospital where relatives of the missing had gathered, Zoe Rapti, Greece's Deputy Minister of Health, told the BBC that investing in the rail network had been made more difficult by the Greek debt crisis around 2010, which led to drastic austerity measures in exchange for a financial rescue by the European Union and the International Monetary Fund.
"Of course, things should have been done during these years but, as you remember, Greece faced a big economic crisis for more than 10 years, which means that many things went back," she said.
She said a "wide investigation" would take place, which she promised would provide answers.
Government spokesman Giannis Oikonomous also said "chronic delays" in implementing rail projects were rooted in "distortions" in the country's public sector going back decades.
© Sakis Mitrolidis / AFP - Getty ImagesFirefighters and Hellenic Train staff members rushed to the scene to snuff out the flames and rescue passengers, the company said.
"He is literally devastated. Since the first moment, he has assumed responsibility proportionate to him," Mr Pantzartzidis said, hinting that the station master, who has not been publicly named, was not the only one to blame.
The country's transport minister has resigned over the incident, saying he would take responsibility for the authorities' "long-standing failures" to fix a railway system that was not fit for the 21st Century.
Meanwhile, the government has promised an independent investigation that it promises will deliver justice.
But Prime Minister Kyriakos Mitsotakis's suggestion that "tragic human error" was to blame has caused anger.
© KONSTANTINOS TSAKALIDIS/BLOOMBERG/GETTYA derailed passenger train is seen following a collision with a cargo train in the Tempe valley near Larissa, Greece, March 1, 2023.
Tear gas was used to disperse protesters, who threw stones and lit fires in the streets.
At a silent vigil in Larissa to commemorate the victims of the incident, one demonstrator said he felt the disaster had been long coming.
"The rail network looked problematic, with worn down, badly paid staff," Nikos Savva, a medical student from Cyprus, told AFP news agency.
The station master arrested should not pay the price "for a whole ailing system", he added.
© Sakis Mitroidis / AFP - Getty ImagesEmergency crews search the wreckage of a crushed wagon Wednesday after a train derailment near Larissa, Greece.
Fire brigade spokesperson Vassilis Varthakogiannis said temperatures inside the first carriage - which burst into flames - had reached 1,300C (2,370F), making it "hard to identify the people who were inside".
Local media have reported that more than 10 people are still missing, as Greece observes three days of national mourning.
Families have given DNA samples to help identification efforts, with the results expected on Thursday.
One of those, a woman called Katerina searching for her missing brother, a passenger on the train, shouted "Murderers!" outside the hospital in Larissa, directing her anger towards the government and the rail company, Reuters reports.
Kostas Malizos, a recently retired surgeon and Emeritus Professor at Greece's University of Thessaly, has returned to work to perform surgery on injured passengers.
"It's a disaster, it's catastrophic," he said. "Families are crying tonight. Unfortunately, the majority of the lost people are young students. They left home, happy after the long weekend, to go for their studies or to see their relatives and never reached them."
As if this is some normal occurrence!