Dozens of masked youths have been clashing with police at a union protest in Athens during a general strike against the cash-strapped government's planned pension and labor reforms. Riot police fired tear gas and stun grenades to disperse troublemakers who threw chunks of marble smashed off a metro station entrance and set rubbish bins on fire. Bus and ferry services have been disrupted, leaving some tourists stranded, in protests against planned pension and labour reforms. The industrial action is another in a series of mass-demonstrations against a swathe of severe austerity measures.