The present invention relates to compounds of formula (I), and their pharmaceutically acceptable salts, solvates, hydrates, geometrical isomers, tautomers, optical isomers or N-oxides, which are inhibitors of SSAO activity. The invention further relates to pharmaceutical compositions comprising these compounds and to the use of these compounds for the treatment of medical conditions wherein inhibition of SSAO activity is beneficial, such as inflammatory diseases and immune disorders.