A protest over the Greek government’s response to the nation’s largest ever train crash turned violent on Friday as Scores of youths hurled rocks and gasoline bombs at police.

Riot police fired volleys of tear gas, stun grenades and water canon at protesters hurling gasoline bombs and smashed-up paving stones in Athens during mass demonstrations Friday to mark the second anniversary of a devastating train crash that has become a symbol of institutional failure in Greece.

Hundreds of thousands of people rallied in cities and towns across Greece on Friday to demand justice on the second anniversary of the country’s deadliest-ever train crash, and striking workers grounded flights and halted sea and train transport.