(CNN) — Demonstrators poured into the streets of Greece after a head-on collision between two trains killed dozens and left scores injured, amid anger over the country’s poor record on railway safety.

Protesters clashed with police in the Greek capital Athens after a passenger train carrying more than 350 people collided with a freight train on Tuesday evening in Tempi, near the city of Larissa, leaving at least 46 people dead and scores injured. The death toll is expected to rise.

The Greek transport minister resigned in the wake of the tragedy, while a rail workers union is going on strike, accusing the government of “disrespect” in the sector.

Another 52 people remain in hospital as a result of the crash, which left toppled carriages and scorched debris in its wake. Six of the injured being treated are in critical condition due to head wounds and serious burns, state-owned public broadcaster ERT reported Thursday.

Most of the passengers involved in the accident were young, a local hospital told ERT. The accident came soon after a holiday weekend.

The identification process of the dead is ongoing alongside recovery efforts involving firefighters and ambulance workers, with the focus on the first carriages of the passenger train, Greek authorities said.

Some of the relatives and friends of missing passengers have published their photos on social media in an appeal for information about their loved ones, CNN affiliate Skai TV reported.

Separately, one relative said his father and brother, who were passengers on the train, are still missing, according to Skai TV. “My brother was 15 years old. He had his life ahead of him. And no one is saying anything about it.”

‘Pain has turned into anger’

Greece has a weak record of railway passenger safety compared with other countries in Europe, recording the highest railway fatality rate per million train kilometers from 2018 to 2020 among 28 nations on the continent, according to a 2022 report from the European Union Agency for Railways.

In an extraordinary meeting, the Greek federation of rail workers decided unanimously to launch the 24-hour strike on Thursday to highlight poor working conditions and chronic understaffing.

It accused the federal government of “disrespect” towards railways for causing the tragic crash, saying “more permanent staff, better training and mainly the implementation of modern security systems, are permanently thrown in the bin.”

Separately, another 24-hour strike was announced by Greek metro workers, who said in a statement: “There are no words to describe such tragedy.”

Greek transport minister Kostas Karamanlis said the railway system the government inherited was “not up to 21st century standards” as he stepped down from his role Wednesday.

In a televised address after visiting the crash site, Greek Prime Minister Kyriakos Mitsotakis said the collision was “mainly” due “to tragic human error.”

He said the transport minister’s decision to resign was honorable, and added that the heads of Hellenic Railways Organization and its subsidiary ERGOSE have also submitted their resignations.

A station manager of a train station in the city of Larissa was arrested in connection to the collision, as part of the investigation into the incident.

The 59-year-old man in question had been charged with mass deaths through negligence and causing grievous bodily harm through negligence, the Larissa police department said.

According to ERT the station manager being questioned for his role in the collision has admitted to “making a mistake.”

Condolences poured in from across the world, while a three-day period of mourning is under way in Greece.

Britain’s King Charles III said in a statement that he and his wife Camilla, Queen Consort, have been “most shocked and profoundly saddened by the news of the dreadful accident.”

French President Emmanuel Macron tweeted: “My thoughts go out to the families of the victims of the terrible accident that took place last night near Larissa. France stands alongside the Greeks.”

Protests erupt in Greece following deadly train collision