School students in the northern Italian city of Vicenza walked out of class last Thursday and bombarded government buildings with tomatoes.
They were protesting at the government's go ahead for the massive expansion of the US military base nearby.
Residents also blockaded the main train station. Protests spread to other Italian cities. Romano Prodi's centre left government approved the US moving 1,600 troops into its Southern European Task Force base.
Over 38,000 US bombing missions took off from the Dal Molin base during Nato's 1999 war on Serbia.
Prodi's decision has created widespread opposition and the biggest division yet in his ruling coalition with Rifondazione Comunista, Greens and other left wingers threatening to break ranks and vote against funding Italy's military contribution to the Nato occupation of Afghanistan.