Greek police fired tear gas at protesters who threw firebombs outside Parliament on Wednesday as tens of thousands demonstrated over the country's worst rail tragedy and called on Prime Minister Kyriakos Mitsotakis to quit.
A freight train crashed head-on with a passenger train, carrying mostly students, on February 28, killing 57 people and leaving 14 others requiring hospital treatment.
More than 40,000 people flooded the streets at the biggest protests in Athens, waving banners that read "It's not an accident, it's a crime" and "it could have been any of us on that train".
Outside Parliament, dozens of masked youths dressed in black hurled Molotov cocktails and stones at riot police, who responded with tear gas, AFP reported.
Demonstrators also torched a van a few blocks away.
In Greece's second city of Thessaloniki, riot police fired tear gas at stone-throwing protesters outside the local railway station.
More than 65,000 demonstrators took to the streets nationwide, police said.
"I am here to pay tribute to the dead but also to express my anger and my frustration," Athens protester Niki Siouta, 54, a civil engineer, told AFP.
"This government must go."
Greek civil servants staged a 24-hour walkout, while doctors, teachers, bus drivers and ferry crew members also went on strike.
Railways were paralysed as train workers extended strike action launched after the accident.
"This government opts to spend money on the police and the army, but not for our safety," said Thanassis Oikonomou, a striking worker and bus union representative.
Greece train disaster latest - in pictures
Last week, in protests sparked by the crash, riot police clashed repeatedly with demonstrators, including in Athens.
Calls are growing louder for Mr Mitsotakis, who is fighting for re-election this spring, to quit over the tragedy, which has highlighted decades of government mismanagement of the rail network.
A station master, who admitted forgetting to reroute one of the trains, has been arrested and charged, but the government has been criticised for seeking to shift the blame mainly on him.
Critics say the station master was inexperienced and was left working alone during a busy holiday period.
They accuse officials of failing to pursue safety reforms on the network.
Greece's Transport Minister, Kostas Karamanlis, resigned on March 1 and Mr Mitsotakis has apologised to victims' families, pledged to get to the root of what happened and embarked on public appearances in a bid to soothe anger.
He visited the crash site and gave a televised address, blaming "human error" for the accident while calling for a special committee of experts to investigate.
But critics have been merciless. Writing in liberal daily Kathimerini, columnist Pantelis Boukalas called Mr Mitsotakis's apology "belated" and said that some might suspect it was "guided by PR gurus".
The Prime Minister and other politicians suspended election campaigning after the tragedy. There is now speculation that the polls, expected in April, could be delayed until May.
Mr Mitsotakis has vowed to seek EU assistance to "finally" modernise the train network.
The executive director of the bloc's rail agency and the European Commission's director for land transport were visiting Athens on Wednesday for talks with Greek officials.
Giorgos Gerapetritis, Greece's acting transport minister, said rail passenger transport might resume by the end of March.
Mr Gerapetritis also conceded that if safety systems had been fully automated, "the accident would not have happened".
Political life will resume on Thursday after a period of national mourning, but Mr Mitsotakis seems to be in no rush to confront the issue of the looming polls.
Asked Monday when he would set an election date, government spokesman Yiannis Economou said: "At this stage, this issue is not on the Prime Minister's mind at all."
