A strike in Finland halted public transportation and shut down ports nationwide on Friday as workers protested against government cutbacks aimed at trying to drag the Nordic country out of a three-year economic downturn. Trains and city buses were not running. Finnair, the national carrier, cancelled 16 domestic flights and airport authorities say delays could be expected. However, ferries, including those to Sweden and Estonia, were running normally. Some shops are expected to be closed during demonstrations later in the day in Helsinki and major Finnish cities.