Athens, Mar 6 (IANS): Greek Prime Minister Kyriakos Mitsotakis has apologised 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 on Sunday, 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 kilometre on the same track in opposite directions.

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

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.

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

Railways employees' labour 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.