Railways employees' labor unions said following the tragedy that they had been warning many officials for long of chronic shortcomings in the network operation, such as understaffing and lack of adequate safety systems.

This photo taken on March 1, 2023 shows the site of a collision of two trains at Tempi municipality, Greece. (Photo/Angelos Tsatsis, Xinhua)

Athens - Greek Prime Minister Kyriakos Mitsotakis apologized on Sunday for the "state's mistakes" following the country's worst train accident which killed 57 and injured dozens.

"As prime minister, I owe everyone, but above all the relatives of the victims, a huge apology. Both personally, and in the name of all those who ruled the country over the years," he said in a press statement, adding that the government "should not hide behind human error."

A station master has been arrested and charged with manslaughter through negligence for the head-on collision of a passenger train with a freight train in central Greece on Tuesday night. The two trains had been running for several kilometers on the same track in opposite directions.

This photo taken on March 1, 2023 shows the site of a collision of two trains at Tempi municipality, Greece. (Photo/Leonidas Tzekas, Xinhua)

Mitsotakis reiterated that justice will be served following an ongoing investigation and immediate steps will be made to improve safety in Greek railways.

The government will ask European Commission and other EU member states to assist providing know-how, as well as additional European funds to upgrade Greece's railways, he said.

Also on Sunday, thousands of people protested in front of the parliament during a rally called by political parties and labor unions, Greek national news agency AMNA reported.

This photo taken on March 1, 2023 shows the site of a collision of two trains at Tempi municipality, Greece. (Photo/Leonidas Tzekas, Xinhua)

Railways employees' labor unions said following the tragedy that they had been warning many officials for long of chronic shortcomings in the network operation, such as understaffing and lack of adequate safety systems.