Thousands of Greeks demonstrated again Sunday to demand a full investigation after the country's worst train collision, as the accident highlighted chronic problems in the railway sector.

The incident, which claimed the lives of a large number of young people, sparked mass protests against the conservative government, as the general elections approached.

For its part, the Greek Public Service Union, one of the unions that called for the demonstration, said, "This crime will not be hidden."

Two days ago, Greek opposition leader Alexis Tsipras accused the government headed by conservative Kyriakos Mitsotakis of "evading its responsibility" and "covering up the truth" about the train accident.

While the prime minister emphasized taking "responsibility," he stressed that "the blame rests with everyone," referring to the responsibility of the various governments in recent years that have been late in modernizing safety systems in the railway sector.

And last Wednesday, tens of thousands participated in a protest march against the accident that occurred on February 28, and resulted in the death of 57 passengers.