VICENZA, Italy , (AFP) - Six policemen were hurt in clashes late Saturday with demonstrators at a rally of more than 3,000 people against the 500-million-dollar enlargement of a US military base in Italy , police said. Some 300 youths, wearing helmets and carrying plexiglass shields, pelted riot cops with rocks and bottles during the American Independence Day demo. The police replied with tear gas and baton charges, AFP photographers said. The work at the base, a former airport in northern Vicenza - which has a current troop capacity of 2,750 - will enable 1,800 soldiers currently based in Germany to be stationed there. Demonstrators who have regularly cut their way through barbed wire guarding the site cried No arms here and We wont be a rear base for the killing of Afghan kids. Local authorities have backed the extension, with around 1,200 jobs created, while successive governments led by centre-left Romano Prodi and current Prime Minister Silvio Berlusconi have each greenlighted the work. A delegation from the organisers - a coalition of Communists, Greens and far-left groups - was to travel to central LAquila later on Sunday to protest at the scene of next weeks G8 summit of world leaders including US President Barack Obama.