(CNN)The insults are crude, but they hit home hard. The players of Koa Bosco have suffered many such racial taunts since their football club was formed in 2013. On occasion, physical violence has even flared on the pitch, says the Italian team's manager Domenico Mammoliti. "The ignorance of some people..." he sighs, revealing a hint of exasperation at the abuse he says his players have endured. Life in the Italian lower leagues is clearly tough. Yet it's nothing compared to the journey undertaken by this team of African immigrants and refugees from countries such as Ghana, Senegal, Gambia, Burkina Faso, Mali, the Ivory Coast, Togo and Sudan.