Athens, Greece (CNN) -- Greek workers were holding a one-day strike Wednesday to protest government efforts to stave off a financial crisis.
Thousands of public-sector workers and their supporters began the 24-hour walkout at 9 a.m. (2 a.m. ET), though local media said workers at Athens' main international airport began their strike at midnight.
Government offices, courts and schools were closed, though public transportation largely continued to operate.
The umbrella civil servants trade union ADEDY, which called the strike, said most of its 500,000 workers were on strike, though that number could not be confirmed. When strikes are called in Greece, non-union members often will join those on the picket lines.
The workers are protesting government plans to raise the age at which workers can claim pensions. The age varies for different public services, but in general, women can retire at 60 and men at 65; the government wants men and women to retire at 65.
The government is also proposing cuts in workers' bonus pay, which for many is a large percentage of their income, as well as a hiring freeze.
Greece's government says the measures are the only way to cut budget deficits and get its national debt under control.
ADEDY Vice President Ilias Vrettakos said he recognizes the government's problem, but that it is not the worker who should suffer. He said the bankers created the problem for Greece, so the bankers should pay.
Vrettakos said the union is willing to compromise only if the government first attacks what the union sees as widespread corruption among top levels of society.
The strike is the first of what is expected to be several across Greece in the coming weeks. Another major strike is scheduled for this month.
Nicole Itano contributed to this report.