With fears mounting of outbreaks of violence on Sunday, which marks one year since a policeman killed a teenager in central Athens, Prime Minister George Papandreou yesterday sought to reassure the nation’s disaffected youth that authorities are «by their side.» Just a few hours later, however, familiar scenes returned to the streets of the capital as youths clashed with police outside a university that authorities had shut down. «We are here to give a message of hope to these youngsters who feel marginalized,» Papandreou said, adding that his government was «against all violence, whether committed by the state or by individuals.» The prime minister then issued an appeal to representatives of student unions to «protect Athens» against a repeat of the unprecedented riots that followed the death of Alexis Grigoropoulos last December 6. But shortly after Papandreou’s speech, clashes erupted outside the Athens University of Economics and Business that authorities had closed down, citing a sharp increase in people testing positive for swine flu. Students reacted to the move, charging the gates. Riot police were dispatched to disperse the youths and fired tear gas. The outburst was contained without any reported injuries. But authorities were yesterday bracing for further tension as students launched sit-ins at several universities including the National Technical University of Athens and Thessaloniki’s Aristotle University. The sit-in at the NTUA was backed by professors there who said the students would keep out self-styled anarchists, blamed for a string of violent attacks on professors.