Athens, December 4 (RHC)-- Greece's biggest workers' unions have staged a 24-hour-long strike against drastic pension cuts planned by the government, bringing public services to a standstill across the country.

Millions of workers launched the industrial action on Thursday, heeding a call by the leaders of the two unions, which cover the public and private sectors. The day also witnessed a thousands-strong march through the capital Athens in support of the protest action, with demonstrators and the police trading fire bombs and stun grenades.

Workers are alarmed as the government plans to roll out a new social security system, under which state-guaranteed pensions will be cut in half -- the minimum standing at EUR 384 (USD 420) -- while supplementary pensions will be conditioned on a person's income and years of social security payments.

The walkout disrupted transportation across the country and shut public offices and state-run schools. Hospitals are also operating only with emergency staff.

In July, the government of Prime Minister Alexis Tsipras agreed to demands by lenders, namely the European Commission, the European Central Bank, and the International Monetary Fund, that the country impose further austerity measures in exchange for a three-year-long EUR 86-billion (USD 93-billion) bailout. The country needs the money to avoid exiting the single-currency eurozone.