Police and academic authorities at the National Technical University of Athens (Polytechnic) went on a state of increased vigilance yesterday ahead of this week’s annual commemoration of the 1973 student uprising that led to the fall of the military dictatorship then ruling Greece. Although the three-day celebrations – which start on Thursday – have been trouble-free for at least two years, authorities are still on guard for the riots that in 1991 and 1995 led to the Patission Street complex’s occupation by anarchists who caused extensive destruction. Turnout is expected to be high this year, particularly during Saturday night’s march to the US Embassy. Throughout the week, students will guard the National Technical University’s buildings, while thousands of riot police will be mobilized during during the march. The group was traveling on an excursion organized by Touchdown Tours, based in Mildenhall in eastern England, which organizes trips to air shows and air force facilities around Europe.