Greece's prime minister on Sunday asked for forgiveness from the families of the 57 dead in the nation's worst rail disaster as thousands of furious protesters rallied in Athens and clashed with police.

"As prime minister, I owe it to everyone, but especially to the victims' relatives, (to ask for) forgiveness," Kyriakos Mitsotakis wrote in a message addressed to the nation ahead of a memorial service in Athens.

"For the Greece of 2023, two trains heading in different directions cannot run on the same line and no one notice," Mitsotakis said in the message posted on his Facebook page.

The crash between passenger and freight trains near the city of Larissa on Tuesday has sparked widespread outrage across Greece.

Protest rallies in Athens and Thessaloniki

On Sunday, railway unions organised a protest rally in central Athens attended by about 12,000 people, according to authorities.

Five people were arrested and seven police officers were injured when a group of more than 200 masked, black-clad individuals started throwing pieces of marble, rocks, bottles and firebombs at officers, according to the Athens police department. Some demonstrators set fire to rubbish bins and threw Molotov cocktails. Others held signs reading "Down with killer governments."

Police at the scene responded with “limited use of the necessary, appropriate means” — that is, tear gas and stun grenades – and chased suspects along a central avenue in the city.

Read more on FRANCE 24 English

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