In this work we present numerical studies and experimental observations of premixed torus-like flames formed around the filament of a steady vortex in a flow of premixed reactants at lean conditions. The numerical results were obtained within the diffusive-thermal model while the experimental observations were carried out for pure methane-air and 50% hydrogen +50% methane-air mixtures. The parallels between such flames and the flame ball are observed owing to delivering of reactants to the curved flame front and removing of combustion products solely by diffusion.