(ANSA) - Rome, July 20 - Local public transport workers went on strike in Italy on Friday in protest over changes to contract conditions. The four-hour walk out was affecting bus, tram and metro services, with times differing from city to city across the country. In Rome the metro A line closed at 08.30 and services were reduced on the metro B line. There were also disruptions to buses, trams and local overland railway services. It is the latest in a long series on end-of-working-week strikes that have caused transport misery for millions in Italy this year.