Gas burner with separate feeding of the flame crowns

Gas burner for cookers, of the type fitted to a cooking hob, comprising a central body, having a first flame distribution ring, and at least one external body, fluidly separated from said central body and substantially concentric with it, having at least one second flame distribution ring, as well as means for separately feeding the mixture of primary air and gas to said central body and to said at least one external body, wherein said means for feeding the at least one external body comprises at least one horizontal mixing chamber with a radial Venturi effect, wherein said horizontal mixing chamber is formed by top and bottom horizontal walls, the bottom wall having an inflow hole at a central portion thereof such that the primary air and the gas flow from the inflow hole radially and generally parallel to the top and bottom horizontal walls.