The February 28 crash in central Greece was the country's worst rail disaster
The February 28 crash in central Greece was the country's worst rail disaster AFP

Some intercity rail travel resumed in Greece on Wednesday for the first time since a head-on collision killed 57 people in the nation's worst rail disaster more than three weeks ago, operator Hellenic Train said.

Several passenger services were back on from early morning.

But the mainline where the crash happened on February 28 -- the country's busiest, spanning 600 kilometres (370 miles) from Athens to the second-largest city of Thessaloniki in the north -- will not reopen until April 1, acting Transport Minister Georgios Gerapetritis said.

Trains were running again from the capital's Piraeus seaport to the international airport, and between Athens and Chalcis on the island of Evia. Two other local services in the Peloponnese region have also started up again, Hellenic Train said.

Few passengers were at hand at the Athens train station to the airport at midday on Wednesday, but those present showed little enthusiasm about boarding.

"I hope this never happens again, that they sort out the railways," said Michalis, a municipal employee who declined to give a surname, adding that the long hours of waiting made train travel "a hardship" even before the accident.

Tassos, who did not wish to give a surname or his job description, said he had "no choice" but to take the train to work.

"The risk is there, basically it's a coin toss," he said.

The return to a full regular schedule of train services will take five weeks.

The disaster sparked weeks of angry and occasionally violent protests, piling pressure on the conservative government of Prime Minister Kyriakos Mitsotakis ahead of elections due in May.

Most of the victims were university students returning from a long holiday weekend.

Greece's transport minister resigned after the disaster.

The stationmaster on duty during the accident and three other railway officials have been charged and face possible life sentences.

Greece's rail watchdog found serious safety problems across the network, including inadequate basic training of critical staff.

Panagiotis Terezakis, the new director general of the state-owned Hellenic Railways Organisation (OSE) that owns the network, said Wednesday that the company "would do everything humanly possible to win back our passengers' confidence".

"We have to move forward after the tragic event that has shaken us all," he told journalists.

On Tuesday, train drivers called for safety assurances including better monitoring of rail crossings, improved tunnel lighting, bridge inspection data and the removal of debris and overgrown vegetation from tracks.

Railway unions had long warned the network was underfunded, understaffed and accident-prone after a decade of spending cuts.

The drivers' union said Tuesday that repeated warnings were "downplayed or not taken seriously."

At the peak of the demonstrations, more than 65,000 people took to the streets nationwide demanding accountability and calling for Mitsotakis's resignation, with some accusing the government of being "murderers".

Many Greeks have been alarmed at the decay of public services amid large-scale privatisation, including passenger and freight trains, to pay off debts stemming from the country's 2009-2018 debt crisis.