Compounds of formula (I): wherein X is O, CH2, S or NH, or the moiety X—R1 is hydrogen; V is CH or N; R1 is hydrogen, C1-6alkyl, C3-7cycloalkyl, aryl, arylC1-6alkyl, heterocyclyl, heterocyclyl-C1-6alkyl, heteroaryl, or heteroarylC1-6alkyl any of which except hydrogen may be optionally substituted; R2 and R3 independently represent hydrogen, C1-6alkyl, C3-7cycloalkyl, aryl, arylC1-6alkyl, heteroaryl, heteroarylC1-6alkyl, heterocyclyl, or heterocyclylC1-6alkyl any one of which except hydrogen may be optionally substituted, or R2 and R3 together with the nitrogen atom to which they are attached form a 4- to 10-membered optionally substituted monocyclic or bicyclic ring; Ar is an aryl or heteroaryl ring either of which may be optionally substituted; one of X1 and X2 is N and the other is NR4, wherein R4 is hydrogen, C1-6alkyl, or arylC1-6alkyl; or pharmaceutically acceptable salts thereof; their use as inhibitors of Raf kinases and pharmaceutical compositions containing them.