EU investigators were looking into a contract that, if carried through, would have placed an electronic control system on the Greek railways, perhaps preventing the train catastrophe that took place earlier in the week, Greek media reported on Saturday.

The Athens-Thessaloniki-Promachona railway's signaling and remote control system update was agreed upon in 2014, but a string of thefts and vandalism stopped the contract's implementation dead in its tracks, Greek online newspaper Documento.gr explained.

According to the report, the European Public Prosecutor's Office has been examining this and a previous contract for the installation of the European Railway Control System for the last four months because the project was partially funded by EU funds.

A spokesperson for the European Prosecutor's Office acknowledged during talks with the Euroactive news website that the contracts were being investigated. They claimed "potential financial interests in the EU" to have been the rationale for legal action.

Lack of rail safety was thrust back into the limelight late Tuesday when a head-on accident between a passenger train and a freight train moving on the same track in central Greece killed at least 57 people. Rail mismanagement in Greece is systemic, according to Greek government spokesperson Ioannis Oikonomou.

As the tragedy's aftermath settles, Greek citizens are demanding answers.

In a statement, the rail workers' union said, "Pain has turned into anger for the dozens of dead and wounded colleagues and fellow citizens." 

Around 2,000 protesters gathered in the northern Greek city of Thessaloniki on Thursday as authorities admitted failures over a deadly train crash on Tuesday, police said as quoted by AFP. 

Left-wing organizations staged two different rallies in central Athens, one of which resulted in skirmishes between stone-throwing youths and riot police. Protests also took place in Thessaloniki and Larissa.

Following the incident, Transportation Minister Kostas Karamanlis resigned, and officials began a judicial investigation to investigate how two trains drove in opposite directions on the same track for more than ten minutes without anyone sounding the alarm.

On Thursday, the Larissa station manager was charged with seven charges of manslaughter and causing serious bodily damage via negligence. His identity has not been revealed.

Following two days of evening protests, 2,000 students took to the streets of Athens on Friday, blocking the road in front of parliament for a moment of silence. Protesters threw petrol bombs and set garbage bins on fire, sparking clashes. Police retaliated with teargas canisters.

Moreover, Greek railway workers extended Saturday a strike that began on March 2 by 48 hours in response to the train accident.

"Due to the 48-hour strike announced by the railway workers' unions, all Hellenic Train services are suspended for Saturday, March 4, and Sunday, March 5," the company said in a statement.