Greek anti-austerity protesters clashed with police Sunday, marring events planned to commemorate the country\'s independence day. The most serious incident was in Heraklion, the capital of the Greek island Crete, where organisers called off a parade to commemorate the 1821 uprising against the Ottoman Empire. Police fired tear gas as hundreds of demonstrators blocked the route set out for the parade, which was then abandonned. \"Holding the parade under police protection and in the presence of tear gas made no sense,\" local official Evripidis Koukiadakis said. In Thessaloniki and Patras, Greece\'s second- and third-largest cities, hundreds of demonstrators marched against strict austerity measures demanded by the European Union and International Monetary Fund. Independence day marches in those cities were not interrupted, though police made about 180 arrests there and across the country. An independence parade in Athens took place without incident after police turned out in force. March 25 commemorates the uprising that led to the end of nearly four centuries of Ottoman rule. Greek authorities are on high alert after several anti-austerity protests in Athens and elsewhere in recent months turned into full-scale riots.