The Red Army of Turin was a Socialist paramilitary organisation set up in September 1919. Their role was to offer military defence to socialist organisations and meetings. One of their first engagements was on 24 September 1919 when they returned gunfire after police and soldiers opened fire on a banned open air demonstration organised by the Socialist Party of Turin against the seizure of Fiume by Italian nationalists led by Gabriele d'Annunzio.
References
Red Army of Turin Wikipedia(Text) CC BY-SA