(15 Nov 2016) Riot police used tear gas and stun grenades in Athens on Tuesday to disperse about 3,000 left-wing marchers protesting President Barack Obama's visit to Greece. The violence broke out as youths in motorcycle helmets and gas masks, armed with wooden clubs and petrol bombs, tried to break a police cordon in front of a barrier formed by police buses. Rioters retired to the Athens Polytechnic university complex in the city centre and engaged in running street fights with police. There is a strong anti-American tradition among Greek left-wingers, who still resent US support for Greece's 1967-74 military dictatorship. Obama's visit comes just two days before the country's main annual anti-American demonstrations. These protests commemorate the bloody suppression, by military authorities, of the Polytechnic pro-democracy uprising. Barack Obama is attending a state dinner hosted by Greece's president, Prokopis Pavlopoulos, in the ballroom of the presidential mansion in central Athens on Tuesday evening. Find out more about AP Archive: http://www.aparchive.com/HowWeWork Twitter: / ap_archive Facebook: / aparchives Instagram: / apnews You can license this story through AP Archive: http://www.aparchive.com/metadata/you...