Police clashed with demonstrators yesterday - and rival demonstrators with each other - during marches in Athens and Thessaloniki commemorating the anniversary of a 1973 student uprising. At least five demonstrators and three policemen were injured in the scuffles in which riot officers fired tear gas at protesters throwing stones and bottles. A total of 46 people were detained, and one demonstrator was arrested for firing flares at riot police in Athens. Another 50 youths had been detained before the rally for bag checks before being released. Officers found several bags containing homemade petrol bombs hidden near trash cans in the city center. Two rival groups of demonstrators - believed to be self-styled anarchists and leftist organizers of the march - also clashed near the US Embassy. In Thessaloniki, youths hurled rocks at riot police from the grounds of Aristotle University before the dean intervened, asking police to back off and pledging to take responsibility for safety in the area. Earlier yesterday a group of representatives from the ruling New Democracy party, visiting Aristotle University's engineering school to lay a commemorative wreath, were attacked by around 40 hooded youths who pelted them with stones. Greek Police Chief Anastassios Dimoschakis insisted that incidents of violence and vandalism were «limited» and congratulated leftist organizers for staging a peaceful march. Some 7,500 police were deployed in Athens alone to control the rally which was attended by about 15,000 demonstrators, including students and trade union members who have staged a series of strikes this year for higher pay.