Thousands of workers walked off their jobs in Greece on Thursday, bringing the country to a halt amid protests against what they say are subpar railway safety standards that led to the deadliest train crash in the country's history.

Unions joined protesters for a 24-hour strike in the capital and beyond, freezing flights, ships and public services. The strike action was the biggest to date in response to last month's train accident.

The accident, which happened just before midnight on February 28, claimed 57 lives and brought to the forefront the debate over plans to install railway safety systems.

Largest protests over the train crash

Protests were held in Thessaloniki, Greece's second-largest city, and Athens the capital where thousands of protestors chanted: "This crime will not be forgotten."

Police sources reported more than 40,000 people protested nationwide, with some 25,000 taking to the streets in Athens alone.

At one point, riot police in Athens clashed with hooded protesters, who hurled firebombs and rocks near parliament on central Syntagma Square. Police used tear gas and arrested six people, and a police officer was slightly injured, Greek media reported.

Many protesters called on the government of Prime Minister Kyriakos Mitsotakis, whose term expires in July, to resign. Some of the banners held during the protests read: "It was not human error, it was crime," and  "Our dead, your profits."

Underground staff and taxi drivers also joined the strikes on Thursday, disrupting urban transport.

Why are people protesting?

Protests have been recurring since the deadly crash, with protesters accusing the government of negligence. The passenger train which collided head-on with a freight train was carrying over 350 passengers, most of them university students. 

A stationmaster and three other railway officials have been charged and an investigation into the crash is ongoing, with authorities blaming it on a "human error." However, public anger has focused on long-running mismanagement of the network.

Calls by unions to increase safety measures have largely gone unheeded, as conservative governments delayed plans for installing safety systems during the past decade.

The crash has also pressured the conservative government ahead of national elections set to take place in the summer.

The government says suspended rail services will restart on March 22 and be restored gradually through April 11. The prime minister has also vowed to offer additional staff to monitor safety and mandatory speed reduction rules along sections of the track.

dmn, rmt/msh (AFP, dpa, Reuters)