 Professional sports in Serbia are organized by sporting federations and leagues (in case of team sports).One of particularities of Serbian professional sports is existence of many multi-sport clubs (called "sports societies"), biggest and most successful of which are Red Star (three world titles and six European in various sports), Partizan (fourteen European titles in various sports), and Beograd in Belgrade, Vojvodina in Novi Sad, Radnički in Kragujevac, Spartak in Subotica.Football is the most popular sport in Serbia, and the Football Association of Serbia with 146,845 registered players, is the largest sporting association in the country.