ATHENS - Riot police in Athens clashed with protesters on Thursday during a demonstration to express outrage over last month’s train tragedy that killed 57 people, AFP reporters said.

Television footage showed the clash broke out at the Greek capital’s central Syntagma Square near Parliament, as a demonstration of some 25,000 people passed by.

The violence broke out when a group of protesters broke off from the rally and hurled petrol bombs at police officers who responded with tear gas. As the demonstrators retreated, they smashed traffic lights and shop windows, and set fire to rubbish bins.

Police said more than 40,000 people protested nationwide on Thursday, including around 8,500 in each of the country’s next largest cities, Thessaloniki and Patras, where another brief clash occurred.

The Feb 28 tragedy exposed decades of safety failings in Greek railways and has put major pressure on the conservative government ahead of national elections.

The rail disaster occurred shortly before midnight when a passenger train crashed head-on into a freight train in central Greece after both were mistakenly left running on the same track.

Most of the passengers were students returning from a holiday weekend.

Thursday’s 24-hour strike was the biggest yet in days of industrial action that followed the disaster, this time called by Greece’s leading private as well as public sector unions.

The walkout shut down the civil service, flights and ferries.

“Things have to change in this country, we simply cannot mourn all these deaths,” said Athens protester Stavroula Hatzitheodorou, who works in the private sector, referring not just to the train disaster but also the deadly wildfires that have gripped Greece in recent years.

“We hope that things will change in these elections,” she said.

A stationmaster and three other railway officials have been charged over the rail disaster.

But public anger has focused on long-running mismanagement of the network and the country has been rocked by a series of sometimes violent mass protests.

Last week, some 65,000 people took part in demonstrations around the country, including around 40,000 in Athens.

In addition to the 57 people who were killed, several victims are still in hospital, including one passenger who is fighting for his life.

The Italian state-owned company operating rail services in Greece, Hellenic Train, said those hurt in the crash and the families of the dead would each get between €5,000 (S$7,100) and €42,000 “to cover immediate needs”.

“This is in no way an admission of responsibility” the company stressed late on Wednesday.

The father of one passenger who died rejected the offer.

“We don’t want their money... This was mass murder, I refuse to accept an apology from murderers,” Mr Pavlos Aslanidis told Alpha TV on Thursday.

“Had this been a serious country, everybody at the Transport Ministry would be in handcuffs,” he said.

Transport minister Kostas Karamanlis resigned after the crash, and Prime Minister Kyriakos Mitsotakis has sought to soothe public anger by repeatedly apologising and vowing to hold a transparent probe.

Rail traffic ground to a complete halt across the country after the incident, although acting Transport Minister Georgios Gerapetritis said that services would gradually resume from March 22.

He said a report by experts investigating the tragedy will be delivered in a month’s time.

Investigators have separately opened a probe into possible mismanagement of railway funds over the past 15 years.

Mr Gerapetritis and former transport ministers will appear before a parliamentary committee next Monday to answer lawmakers’ questions on the tragedy.

With public anger mounting before elections expected in May, Mr Mitsotakis has seen a 7.5-point lead in the polls slashed to just over 3 per cent in recent surveys.

He has come under fire for blaming “human error” for the collision and the stationmaster on duty at the time, who allegedly routed the trains onto the same stretch of track by accident.

But railway unions had long been warning about problems on the underfunded and understaffed train network.

Mr Mitsotakis had been expected to set an April election date. Ballots are now expected in May. AFP