The invention relates to antibacterial compounds of formula (I) wherein U represents CH or N; W represents CH or N; R1 represents alkoxy, halogen or CN; ring A represents a pyrrolidin-1,3-diyl-, a piperidin-1,3-diyl or a morpholin-2,4-diyl group and B represents CH2; or ring A is selected from the groups drawn below: wherein R2 represents H, F or hydroxymethyl, and B is absent; G represents a group selected from the group consisting of  —CH═CH-E, wherein Y1, Y2, Y3 and Z independently represent CH or N; Q represents O or S; and E represents phenyl which is mono- or di-substituted wherein the substituents are each independently halogen; and to pharmaceutically acceptable salts of such compounds.