The present disclosure provides compounds of the general formula (I), their salts and N- oxides, and solvates and prodrugs thereof (wherein the characters are as defined in the description). The compounds of the general formula (I) are inhibitors of Factor XIa, so that they are useful in the prevention of and/or therapy for thromboembolic diseases. An example of the compound is methyl [4-(2-{ (3S)-7-[5-chloro-2-(1H-tetrazol-1-yl)phenyl]-5-oxo-1,2,3,5-tetrahydro-3-indolizinyl} -1H-imidazol-4-yl)phenyl]carbamate.