ATHENS: A Greek railway employee was jailed on Sunday pending trial over a deadly train crash that killed at least 57 people, as Greeks seethed with anger over the worst rail disaster in living memory.

Protests continued to reverberate days after a head-on collision of a passenger train and a freight carrier on the Athens-Thessaloniki route late in the evening of Feb. 28.

Clashes erupted between police and demonstrators in Athens on Sunday, after thousands rallied to protest over the crash.

The 59-year-old Larissa station master faces multiple charges of disrupting transport and putting lives at risk.

The man, who cannot be named under Greek law, was questioned for seven hours before a magistrate on Sunday before being detained.

"For about 20 cursed minutes he was responsible for the safety of the whole of central Greece," his lawyer Stefanos Pantzartzidis said.

On Thursday, Pantzartzidis said that his client was devastated and had assumed responsibility "proportionate to him" but other factors were also at play, without elaborating.

Railway workers say the country's rail network has been creaking under cost-cutting and underinvestment, a legacy of Greece's debilitating debt crisis from 2010 to 2018.

Prime Minister Kyriakos Mitsotakis, who blamed the crash on human error, acknowledged that decades of neglect could have contributed to the disaster.

"As prime minister, I owe everyone, but most of all the relatives of the victims, an apology," he wrote on his Facebook account. "Justice will very fast investigate the tragedy and determine liabilities."

After protests over the past three days across the country, some 10,000 people gathered in an Athens square on Sunday to express sympathy for the lives lost and to demand better safety standards on the rail network.

"That crime won't be forgotten," protesters shouted as they released black balloons into the sky. A placard read: "Their policies cost human lives."

Railway workers' unions say safety systems throughout the rail network have been deficient for years as a remote surveillance and signalling system has not been delivered on time. They have called on the government to provide a timetable for the implementation of safety protocols.

Mitsotakis said on Sunday that if there had been a remote system in place throughout the rail network "it would have been, in practice, impossible for the accident to happen".